VictorJuiz/thesis huggingface dataset:
Inhibition of Transthyretin Fibrillogenesis Using a Conformation Specific Antibody
Keywords: Transthyretin
Senile Systemic Amyloidosis
Familial Amyloid Polyneuropathy
Familal Amyloid Cardiomyopathy
Antibody Design

Immunoglobulin-mediated inhibition of amyloid fibril formation in vivo is a promising strategy for the treatment of protein misfolding diseases such as the amyloidoses. Here we focus on transthyretin amyloidoses, a group of protein conformation diseases caused by the misfolding of the serum protein transthyretin into fibrillar structures that deposit in specific organs and tissues—often with serious pathological consequences. Using a structure-guided immunological approach, we report a novel antibody that selectively recognizes monomeric, misfolded conformations of transthyretin in vitro. Raised to an epitope normally buried in the native form of transthyretin, this antibody was found to suppress transthyretin fibrillogenesis at substoichiometric concentrations in vitro. Overall, the selectivity and inhibitory nature of the antibody signals the potential use of conformation specific antibodies in the diagnosis and treatment of transthyretin amyloidoses, conditions which remain difficult to treat and are widely under/misdiagnosed at the current time.
Dealloying and Formation of Nanoporosity in Noble-metal Alloys
Keywords: Dealloying
Nanoporosity

Nanoporosity formation by selective dissolution of Ag-5 at. pct Au in perchloric acid has been investigated with regards to the mechanism of stress-corrosion cracking (SCC), film-induced cleavage in particular. It has been proven that dealloying of silver-gold systems containing low concentration of gold leads to the formation of a three dimensional nanoporous layer and that it can be carried out in a broad range of potentials and concentrations of a dealloying solution. Therefore, stress-corrosion cracking observed in these alloys may be caused, initiated or at least accompanied by the formation of nanoporosity resulting from dealloying. These results will have impact on the fabrication of cheaper nanomaterials where there is required large surface to volume ratio with gold as the outermost layer. Understanding the role of dealloying will also help us to design new materials of higher resistance against stress-corrosion cracking.
Oxidative Palladium(II)-catalyzed Arene C-H Bond Functionalization and Progress towards the Total Synthesis of 6-Deoxyerythronolide B
Keywords: oxidative cross coupling
total synthesis

To address the issue of unnecessary functional group transformations in synthesis, the direct functionalization of carbon-hydrogen (C―H) bonds presents itself as an efficient and atom economical process. In particular, palladium(II)-catalyzed oxidative functionalization of arene C–H bonds were investigated to yield intermolecular and intramolecular arylations. Kinetic studies and characterization of bimetallic palladium(II) complexes led to the discovery of two other palladium(II)-catalyzed processes: arene hydroxylation and selective chlorination of anilides. Realizing the potential of biocatalysis and of transition-metal catalysis, we marriaged these two fundamentally different methods to access complex molecules in rapid and step economical ways and chose popular synthetic target, 6-deoxyerythronolide B to showcase the efficiency of these stereoselective reactions. To form the 14-membered lactone, we employed a transition-metal catalyzed ring-closing metathesis. Two different fragments were assembled via traditional and reliable aldols, oxidations and reductions, crotylations and protective group chemistry.
Evaluating a New Display of Information Generated from LiDAR Point Clouds
Keywords: LiDAR
teleoperation
point clouds
interface

The design of a texture display for three-dimensional Light Detection and Ranging (LiDAR) point clouds is investigated. The objective is to present a low fidelity display that is simple to compute in real-time, which utilizes the pattern processing capabilities of a human operator to afford an understanding of the environment. The efficacy of the display is experimentally evaluated by in comparison with a baseline point cloud rendering. Subjects were shown data based on virtual hills, and were asked to plan the least-steep traversal, and identify the hill from a set of distractors. The major conclusions are: comprehension of LiDAR point clouds from the sensor origin is difficult without further processing of the data, a separated vantage point improves understanding of the data, and a simple computation to present local point cloud derivative data significantly improves the understanding of the environment, even when observed from the sensor origin.
Regulating BCA2: An Investigation into E3 Ligase Activity
Keywords: E3 Ligase
BCA2
breast cancer

The BCA2 E3 ligase is expressed in a majority of invasive breast cancers. BCA2 has inherent autoubiquitination activity which contributes to cell migration and proliferation processes. Here, ten novel BCA2 binding proteins were found using yeast and bacterial screening. Two of which were human homolog of Rad23 variant A (hHR23a) and 14-3-3σ. In vivo and in vitro assays confirmed that both hHR23a and 14-3-3σ bound BCA2 and were co-expressed with BCA2 in breast cancer cells. Interaction of BCA2 with hHR23a and 14-3-3σ affect the autoubiquitination and auto-degradation activity of BCA2. Multi-ubiquitination of hHR23a-bound BCA2 was dramatically lower than that of free BCA2, this corresponded to increased BCA2 expression and half-life. Furthermore, phosphorylated BCA2 protein was stabilized by interaction with 14-3-3σ, via substrate inhibition of BCA2 autoubiquitination. High expression of BCA2 is correlated with grade in breast cancer and regulation of this E3 ligase’s activity may be important to cancer progression.
Signal-dependent Translation of the Platelet Transcriptome: The Roles of αIIbβ3 Integrin, Fibrinogen and Fibronectin in Platelet de novo Protein Synthesis
Keywords: protein synthesis
fibrinogen
fibronectin
P-selectin
αIIbβ3 integrin
GPIIb-IIIa

Although platelets are anucleate, they do inherit 1500-3000 mRNA transcripts from their megakaryocyte progenitors, in addition to all the machinery essential for protein synthesis; however, there is little understanding why platelets initiate de novo synthesis of these transcripts. Our group demonstrated that fibrinogen (Fg), a ligand of platelet Glycoprotein (GP)IIb-IIIa (αIIbβ3 integrin), is required for platelet P-selectin expression and that engagement of Fg with GPIIb-IIIa is essential for this process. The present study shows that murine platelets incubated with Fg synthesize P-selectin de novo, and this synthesis is blocked by puromycin. A similar effect is also observed when platelets are incubated with fibronectin, another ligand of GPIIb-IIIa. Furthermore, platelets from both ligand- (Fg−/−, von Willebrand factor−/−, apolipoprotein A-IV−/−) and GPIIb-IIIa-deficient mice have altered proteomes. These data suggest an intricate mechanism by which engagement of platelets with their environment triggers signal-dependent translation of the platelet transcriptome, consequently altering the platelet proteome.
Possible Role of Osteoblasts in Regulating the Initiation of Endochondral Repair Process during Fracture Healing
Keywords: Fracture repair
Endochondral Ossification
Osteoblast
Osteoclast
Chondrocyte
Herpes simplex virus thymidine kinase
Gacnciclovir

Fracture repair is a regenerative event that involves the precise coordination of a variety of cells for successful healing process. Within the microstructure hierarchy of bone repair, the predominant cells involved include the chondrocytes, osteocytes, osteoblasts, and osteoclasts. Although the role of osteoblasts during fracture healing has been previously shown, their role during the initiation phase of endochondral fracture repair remains unclear. In order to study the role of osteoblasts during fracture repair, we used a transgenic mouse model expressing the herpes simplex virus thymidine kinase gene in early differentiating osteoblasts, which allows conditional ablation of cells in osteoblastic lineage upon treatment with the Gancicolvir drug. Results from this study suggest that not only are osteoblasts required in later stages of fracture repair as the medium for bone synthesis, and osteoclast activation during bone remodelling, but could also be required for the initiation and advancement of the endochondral ossification process.
Diagnostic Accuracy of MRI for Assessment of T-category, Lymph Node Metastases, and Circumferential Resection Margin Involvement in Patients with Rectal Cancer: A Systematic Review and Meta-analysis
Keywords: Rectal cancer
Magnetic resonance imaging
Diagnostic accuracy
Staging
Meta-analysis

BACKGROUND: MRI is increasingly being used for rectal cancer staging. The purpose of this study was to summarize published evidence to determine the accuracy of MRI for T-category, lymph node (LN) metastases, and circumferential resection margin (CRM) involvement in rectal cancer. METHODS: Sensitivity, specificity, and diagnostic odds ratios (DOR) were estimated using hierarchical summary receiver operating characteristics modeling and bivariate random effects modeling. RESULTS: MRI was more specific for CRM (94%, 95%CI 88-97) than for T-category (75%, 95%CI 68-80) and LN’s (71%, 95%CI 59-81) but was more sensitive for T-category (87%, 95%CI 81-92) than for CRM (77%, 95%CI 57-90) and LN’s (77%, 95%CI 69-84). DOR was higher for CRM (56.1, 95%CI 15.3-205.8) than for LN’s (8.3, 95%CI 4.6-14.7) and T-category (20.4, 95%CI 11.1-37.3). CONCLUSIONS: MRI has good accuracy for both CRM and T-category and should be considered for preoperative rectal cancer staging. In contrast, LN assessment is poor on MRI.
Immigration Status and Mental Health: Invisible Lives and Hidden Realities of Undocumented Youth: A Pilot Study
Keywords: Nonstatus
Development

Individuals with no immigration status are one of the fastest growing migrant populations in Canada, totaling over half a million. Yet, there has been little empirical research on the developmental impacts of living without formal immigration status. In the present study, 47 non-status adolescents were interviewed about their general experiences of growing up in Canada without status, to examine the mental health and developmental impacts particular to this population. Results from the study indicated that lack of immigration status is implicated in significant developmental impairments. Lack of immigration status is associated with difficulties with identity formation and consolidation, compromised self-efficacy, acculturative stress and compromised peer relations, which in turn results in poorer developmental and mental health outcomes. Findings are discussed in terms of both theoretical and practical implications, and directions for future research are outlined.
Adolescent Social Perspective Taking in Contexts of Social Justice: Examining Perceptions of Social Group Differences
Keywords: social perspective taking
social justice
adolescent development
social cognition

The present mixed-methods study examined adolescents’ social perspective taking in contexts of social justice as demonstrated by their awareness and interpretations of hypothetical peer interactions depicting racism and sexism. Fifty adolescents in Grades 9 and 12 participated in a semi-structured interview in which they were presented with two scenarios, involving adolescents in conflicts portraying racism and sexism. They were asked a series of questions designed to elicit their awareness and understanding of social group differences. Qualitative analyses revealed three categories of adolescents’ responses, reflecting distinct interpretations of social group differences. On average, adolescents assumed a perspective that was naïve to the disparities existing between vulnerable and less vulnerable social groups. Furthermore, it was shown that older adolescents had significantly more sophisticated social justice understandings than younger adolescents. These findings highlight the need to educate adolescents about issues of social justice and facilitate an appreciation of social group differences.
The Relationship between Reading Comprehension and Adolescents with and without ADHD
Keywords: ADHD
comprehension

This study examined reading comprehension in adolescents with and without attention deficit hyperactivity disorder (ADHD). Forty-five youth with ADHD (26 males, 19 females) and 42 adolescents without ADHD (20 males, 22 females) between the ages of 13 and 18 completed standardized tests of achievement. The results of multiple regression analyses indicated that orthographic and semantic abilities were related to reading comprehension. Both the orthographic (i.e., spelling) measure and the semantic (i.e., oral vocabulary) measure explained unique amounts of variance on the reading comprehension measure. Next, it was found that adolescents with ADHD were significantly more likely to have a Specific Reading Comprehension Disability (S-RCD) than adolescents without ADHD. Last, it was found that adolescents with ADHD and an S-RCD demonstrated poorer performance on academic measures that depend in part on comprehension (e.g., math problem solving) than adolescents with ADHD without an S-RCD.
Lecithin-linker Microemulsion-based gels for Drug Delivery
Keywords: lecithin microemulsion
microemulsion-based gel
transdermal drug delivery
ophthalmic drug delivery

Microemulsions have gained interest from the pharmaceutical industry due to their ability to co-solubilize hydrophilic and lipophilic drugs, and to provide enhanced drug penetration. In this work, thermosensitive gelatin- and poloxamer 407-stabilized microemulsion-based gels (MBGs) were formulated using alcohol-free, low toxicity and low viscosity lecithin-based linker microemulsions. The addition of gelatin to water-rich bicontinuous microemulsions induced the formation of clear viscoelastic gels containing an oil-rich microemulsion as the gelatin seemed to dehydrate the original microemulsion. The addition of poloxamer 407 to water-continuous microemulsions produced MBGs with different gelation temperatures. High concentrations of lipophilic components in the microemulsion, particularly the oil, reduced sol-gel transition temperature, while hydrophilic components increased sol-gel transition temperature. Gelatin and poloxamer MBGs provided desirable viscoelastic properties for ophthalmic and transdermal applications with minimal impact on the transport properties of the original microemulsions.
Molecular Mechanisms of p63-Derived Ectodermal Dysplasia
Keywords: p63
Ectodermal Dysplasia
p53 Family
Protein Stability
Transactivation
Itch
PERP
EEC

Molecular defects in the p63 gene give rise to severe physiological abnormalities in patients with ectodermal dysplasia, however the mechanisms by which p63 mutations disrupt p63 function are unknown. In this study we examined four ΔNp63α mutants; Ectrodactyly-Ectodermal Dysplasia with Clefting (EEC) R204W, R304W and Ankyloblepharon-Ectodermal Dysplasia with Clefting (AEC) mutants, L514F and G530V, and characterized DNA binding, transcription factor activity, oligomerization with wild-type p63 and changes in protein stability/nuclear localization. We also investigated the putative OD-SAM interaction in p63 and p73. We demonstrated that both the EEC and AEC mutants cannot transcriptionally activate the PERP promoter and can hetero-oligomerize forming dominant negative complexes with wild-type p63. We show that both EEC mutants and AEC L514F mutants are more stable which is not due to aberrant degradation by the E3 ligase Itch. Finally, we discovered that a novel interaction between the p73 OD and SAM domain is absent in p63.
Inhibitory Actions of Gastrin-releasing Peptide in Mouse Anterior Cingulate Cortex
Keywords: Gastrin-releasing peptide
Anterior cingulate cortex

The anterior cingulate cortex (ACC) expresses high density of Gastrin-releasing peptide (GRP) and GRP receptor mRNA. To address possible function, this investigation used patch clamp recordings in mouse brain slice preparations to evaluate intrinsic properties of ACC neurons and neuronal responses to bath-applied GRP peptide. The ACC neurons were divided according to their morphology, the properties of action potentials and their firing pattern in response to depolarizing current pulses. Two physiological groups of interneurons and three groups of pyramidal neurons were defined. Application of the GRP induced depolarization and increased firing of the interneurons while hyperpolarization and reduced firing in pyramidal neurons. Moreover, activation of GRP receptor facilitated GABAergic neurotransmission via a postsynaptic mechanism. The results suggest that GRP receptor is an important regulator of neuronal circuits in the ACC and may consequently play an important role for ACC neurons in the central processing of high brain function.
Molecular Genetic Analysis of the Mouse Anorexia Mutation
Keywords: serotonin
mouse

The serotonergic system regulates numerous behaviours and disruptions in this system have been associated with disorders of mood and mind. Although molecular genetic analysis has dissected many of the genes involved in the specification of the serotonergic system, relatively little is known about the mechanisms that promote axonal outgrowth from serotonin-producing neurons and how these projections are directed to innervate and form synapses with their appropriate targets. The mouse anorexia mutation causes hypersprouting of serotonergic projections in target fields and has provided us the unique opportunity to examine the crucial events that lead to the establishment of these complex serotonergic networks. Through positional cloning, I have identified a candidate gene that is upregulated during a time in which innervation and synaptogenesis of serotonergic neurons are maximal. I have assessed the expression of this candidate gene in the brain and have found striking differences in the pattern of expression between the normal and the mutant mouse. Furthermore, by using transgenic methods, I have partially rescued several hallmark behavioural phenotypes in the mutant mouse. Thus, this candidate almost certainly represents the “Anorexia” gene.
Acting and Second Language Pragmatics: Pedagogical Intersections
Keywords: drama
second language
education
L2
acting
performance
pedagogy
case study
sociolinguistics
pragmatics
pragmatic competence
sociolinguistic competence
intonation
theatre
foreign language
musical
adult education
second language education

The study sheds light on the interrelations between interlanguage pragmatics and the use of a popular acting method, the Stanislavsky System, for second language (L2) acquisition. The theoretical investigation explores various uses of acting in second language education. The empirical enquiry represents an exploratory case-study of two adult EFL learners attending a theatre course in English. Through teacher journals, interviews, and the analysis of the students’ pragmatic performance as captured by a video camera, the researcher hypothesizes that the pragmatic development of the students involved in drama comes from three main sources: the script, the acting exercises, and the necessity to communicate in English during the theatre course. In all three cases, the zone of proximal development in relation to pragmatic competence emerged as a result of a teacher-generated impetus to use L2, numerous opportunities for imitation and repetition, continuous peer-support, and the collaborative spirit created in the classroom.
Refining Positional Identity in the Vertebrate Hindbrain
Keywords: hindbrain development
segmentation

The vertebrate hindbrain is divided early in embryogenesis along its anterior-posterior axis into eight segments known as rhombomeres. This provides an excellent model for studying early segmentation and region-specific transcriptional domains. MafB, a basic domain leucine zipper transcription factor, is the first gene known to be expressed in the presumptive rhombomere 5 and 6 domain (r5-r6). MafB expression is directly activated by the homeodomain protein vHnf1. vHnf1 and MafB share an anterior expression limit at the r4/r5 boundary but vHnf1 expression extends beyond the posterior limit of MafB and, therefore, cannot establish the posterior expression boundary of MafB. Through the use of in situ hybridization, immunofluorescence, and chromatin immunoprecipitation analyses, I have determined that the caudal-related homeodomain protein Cdx1 establishes the posterior boundary of MafB by directly inhibiting expression beyond the r6/r7 boundary. My results indicate that MafB is one of the earliest direct targets of Cdx1.
Protecting Group-free Synthesis of Glycosides
Keywords: Protecting group-free glycosidations
Unprotected glycosyl chlorides
Glycosyl donors

Carbohydrates play major roles in many biological processes. Therefore, the synthesis of oligosaccharides is of considerable interest for biological, medicinal, and pharmacological studies. Many approaches have been developed for the synthesis of oligosaccharides, in which the main focus is often the formation of the glycosidic bonds. Traditional approaches use protecting group strategies that can be time consuming and can result in poor overall yield. This thesis describes the protecting group-free synthesis of a series of glycosyl donors of a range of mono- and disaccharides. These donors can be used to synthesize unprotected glycosyl chlorides, observed in situ. Reaction of the glycosyl chlorides with a variety of nucleophiles afforded the expected displacement products, giving access to a range of O-, N-, and S-linked glycosides, without resorting to the use of protecting groups.
Investigating the Neurobiological Role of Tubby, a Protein Involved in Obesity
Keywords: Tubby

Tubby mice succumb to blindness, deafness, and obesity. Vision and auditory deficits are attributed to neurodegeneration and tubby-associated obesity has been postulated to result from neuronal deficits in brain regions controlling weight regulation. TUB has been implicated in Gq signaling and 2 isoforms of TUB, found exclusively in the brain, may have opposing effects on transactivation. Toward this end, I developed several cell culture assays to interrogate TUB function and found that TUB directs neuronal outgrowth in an isoform-specific manner. One isoform directs stable and polar outgrowth while the other directs multiple process outgrowths and branching. These effects can occur via Gq signaling and require nuclear localization. Furthermore, I have found that the serotonergic system of tubby mice displays morphological and innervation deficits. Since the serotonergic system is implicated in modulating moods and behaviours, including appetite, these deficits may result in the obesity and motivational issues observed in tubby mice.
Group 4 Metal Complexes with Ferrocenyl Amidinates
Keywords: organometallics
polymerization catalysis

Bis(amidinate) dichloride complexes of the type M(L)2Cl2 (M=Zr, 2a; M=Ti, 2b; L=CyNC(C5H5FeC5H4)NCy) were synthesized by treating 2 equiv of ferrocenyl amidine, H(L), with M(NMe2)2Cl2 (M=Ti, Zr.2THF). Half sandwich mono(amidinate) complexes, Cp’ZrLCl2 (Cp’=Cp, 2c; Cp’=Cp*, 2d), were prepared by the reaction of Cp’ZrCl3 with 1 equiv of Li(L). The dialkyl complexes, M(L)2Me2 (M=Zr, 3a; M=Ti, 3b), CpZr(L)(CH2Ph)2 (3c) and Cp*Zr(L)Me2 (3d) were prepared by treatment of the dichloride complexes (2a-2d) with an appropriate alkylating agent. The dichloride complexes (2a-2d) activated with MAO, and dialkyl complexes (3a-3d) activated with B(C6F5)3 and [Ph3C][B(C6F5)4] show low to moderate ethylene polymerization activities. Cyclic voltammetry studies on the metal complexes containing ferrocenyl amidinates reveals quasi reversible oxidation and reduction waves for the ferrocene/ferrocenium couple.