VictorJuiz/thesis huggingface dataset:
The Role of Concepts in Perception
Keywords: Perception, Concepts, Epistemology, Kant, Color, Shape, Justification, Crossmodal Experience, Vision

The claim of my dissertation is that some basic concepts are required for perception. Non-basic concepts, we acquire, and I give an account as to how that process changes our perception. Suppose you are looking at the Mona Lisa. It might seem that you can perceive a lot more shades of color and a lot more shapes than for which you possess precise concepts. I argue against this. For every color or shape in appearance you have the ability to categorize it as that color or shape. It’s just that this is done by your sensory system prior to appearance. I argue that empirical studies show this. Blindsighted patients, for instance, are blind in part of their visual field. But they can use color and shape information received through the blind portion. I take this, along with other studies, to show that once you perceive a color or shape, it has already been categorized. I then argue that we perceive only low-level properties like colors and shapes. For in-stance, we don’t perceive high-level kind properties like being a table or being a wren. I do think that wrens or tables might look different to you after you become disposed to recognize them. Some take this to show that being a wren or being a table can be represented in your perception. I argue that this inference does not follow. If you are not disposed to recognize wrens, but we track the attention of someone who is, and we get you to attend to wrens in that same way, your visual phenomenology might be exactly the same as theirs. But there is no reason to think that it represents a wren. After all, you lack a recognitional disposition for wrens. I take this and other arguments to show that we perceive only low-level properties like colors and shapes.
Bacterial Adhesin Proteins Associated with Microbial Flocs and EPS in the Activated Sludge
Keywords: adhesin proteins
flocs

Microbial flocculation is important in wastewater treatment process for an efficient separation of the solid and liquid phases and the removal of organics. Bacterial adhesins may contribute to the formation of microbial flocs since they have been previously found to play a significant role in the formation of biofilms. The overall objective of this work was to analyze bacterial protein adhesins present in the extracellular polymeric substances (EPS), mainly those associated with pili, fimbriae, flagella, and curli, and to determine their role in microbial floc structure and function. Identification of these EPS adhesins may explain their role in biofouling and enhance our understanding regarding the manipulation of bioflocculation. With the exception of flagellin protein FliC, which was distributed towards the outer region of the floc, all the adhesins appeared to be concentrated within the core region of the floc. Antibody staining coupled with confocal microscopy indicated that adhesin proteins associated with flagella (FliC), pili (PilA), fimbriae (FimH), and curli (CsgA, CsgB) represent a significant fraction (10-27%) within microbial flocs. Western blot analyses demonstrated that with the exception of FliC, all the studied adhesins were detected in the EPS matrix. Furthermore, mass spectrometry indicated the presence of pili in the EPS matrix. Under Phosphorus (P)-limited conditions, with the exception of fliC, all the studied genes (fimH, pilO, psiF) exhibited a change in response to P reduction, with fimH gene at the highest expression and an earliest response (1 d). During the nutritional downshift analyses, fimH and pilO genes were expressed within the first six hours of the reaction at significantly greater levels than during P-limited conditions. Taken together, these studies suggest that adhesins associated with pili, fimbriae, and curli play an important role in initial floc formation, and that adhesins associated with flagella either recruit planktonic bacteria to a growing floc or are involved in the interfacial relationships at the floc surface. This information may assist researchers and engineers in broadening the understanding of bioflocculation in conventional biologically based wastewater treatment systems and in advanced technologies, such as hybrid and membrane bioreactors. In addition, this knowledge will be useful in creating molecular tools to aid in the design and monitoring of bioflocculation.
A Comparison of Two Methods of Adjusted Attributable Fraction Estimation as Applied to the Four Major Smoking Related Causes of Death, in Canada, in 2005
Keywords: attributable fraction
adjustment
attributable death
confounder
modifier
covariate

The main objective of the thesis was to compare two methods of calculating adjusted attributable fractions and deaths as applied to smoking exposure and four health outcomes, lung cancer, ischaemic heart disease, chronic obstructive pulmonary disease, and cerebrovascular disease, for Canadians 30 years or older in the year 2005. An additional objective was to calculate variance estimates for the evaluation of precision. Such estimates have not been published for Canada to date. Attributable fractions were calculated using the fully adjusted method and the partial adjustment method. This method requires confounder strata specific (stratified) estimates of relative risk, along with accompanying estimates of variance. These estimates have not previously been published, and were derived from the Cancer Prevention Study II cohort. Estimates of the prevalence of smoking in Canada were obtained from the Canadian Community Health Survey 2005. Variance estimates were calculated using a Monte Carlo simulation. The fully adjusted method produced smaller attributable fractions in each of the eight disease-sex-specific categories than the partially adjusted method. This suggests an upwards bias when using the partial adjustment method in the attributable fraction for the relationship between cigarette smoking and cause-specific mortality in Canadian men and women. Summed across both sexes and the four smoking related causes of death, the number of deaths attributable to smoking was estimated to be 25,684 using the fully adjusted method and 28,466 using the partial adjustment method, an upward bias of over ten percent, or 2,782 deaths. It is desirable, theoretically, to use methods which can fully adjust for the effect of confounding and effect modification. Given the large datasets required and access to original data, using these methods may not be feasible for some who would wish to do so.
Mathematical Theory of van der Waals forces
Keywords: van der Waals forces

The van der Waals forces, which are forces between neutral atoms and molecules, play an important role in physics (e.g. in phase transitions), chemistry (e.g. in chemical reactions) and biology (e.g. in determining properties of DNA). These forces are of quantum nature and it is long being conjectured and experimentally verified that they have universal behaviour at large separations: they are attractive and decay as the inverse sixth power of the pairwise distance between the atoms or molecules. In this thesis we prove the van der Waals law under the technical condition that ionization energies (energies of removing electrons) of atoms are larger than electron affinities (energies released when adding electrons). This condition is well justified experimentally as can be seen from the table, \newline \begin{tabular}{|c|c|c|c|} \hline Atomic number & Element & Ionization energy (kcal/mol)& Electron affinity (kcal/mol) \\ \hline 1 & H & 313.5 & 17.3 \\ \hline 6 & C & 259.6 & 29 \\ \hline 8 & O & 314.0 & 34 \\ \hline 9 & F & 401.8 & 79.5 \\ \hline 16 & S & 238.9 & 47 \\ \hline 17 & Cl & 300.0 & 83.4 \\ \hline \end{tabular} \newline where we give ionization energies and electron affinities for a small sample of atoms, and is obvious from heuristic considerations (the attraction of an electron to a positive ion is much stronger than to a neutral atom), however it is not proved so far rigorously. We verify this condition for systems of hydrogen atoms. With an informal definition of the cohesive energy $W(y),\ y=(y_1,...,y_M)$ between $M$ atoms as the difference between the lowest (ground state) energy, $E(y)$, of the system of the atoms with their nuclei fixed at the positions $y_1,...,y_M$ and the sum, $\sum_{j=1}^M E_j$, of lowest (ground state) energies of the non-interacting atoms, we show that for $|y_i-y_j|,\ i,j \in \{1,...,M\}, i \neq j,$ large enough, $$W(y)=-\sum_{i<j}^{1,M} \frac{\sigma_{ij}}{|y_i-y_j|^6}+O(\sum_{i<j}^{1,M} \frac{1}{|y_i-y_j|^7})$$ where $\sigma_{ij}$ are in principle computable positive constants depending on the nature of the atoms $i$ and $j$.
Exploring the Nature and Extent of Leadership Distribution in Elementary Schools
Keywords: distributed leadership
leadership
elementary school
collaboration
quantitative
multi-level modeling
HLM
school leadership
educational leadership
teacher leadership

This study explored forms of distributed leadership in schools and the relationship between these forms and various personal and organizational factors. Though all empirical constructs used in this study were carefully grounded in the existing literature on the topic, the organization and empirical investigation of these constructs in a systemic manner is a distinct contribution of the study. The research was conducted in one large Ontario district that had been promoting distribute leadership for years. The evidence consisted of the surveys of 92 principals, 52 vice-principals, and 2190 teachers from the district’s elementary schools. Various statistical analyses, including descriptive, correlation, regression, and multi-level modeling analyses, were used to analyze the gathered data. In the study schools, administrators and teachers perceived leadership for high-priority school initiatives being mostly distributed in an egalitarian and coordinated manner. They also associated this coordinated way of distribution with wider distribution of leadership. At the same time, teachers often experienced leadership being distributed by principals in an authoritative manner as well. This finding indicates that principal delegation remains a dominant form of leadership and should be studied alongside more egalitarian distributed forms. This research brings to light the differences in principals’, vice-principals’, teacher-leaders’, and classroom teachers’ experiences with distributed leadership. It is recommended for researchers to take into account these differences in their studies of school leadership. District and school leaders should also consider staff’s varied leadership experiences while developing distributed leadership forms in schools. The study also suggests that school conditions have more effect on the way leadership gets distributed in schools than personal beliefs and experiences of principals, vice-principals, and teachers do. This implies that in order to develop extensive and coordinated distributed leadership forms, which are believed to be more productive, school administrators should devote considerable effort to encourage teachers’ engagement in leadership activities, build cultures of trust and collaboration, develop structures supporting shared decision making, ensure staff’s commitment to shared goals and provide incentives and relevant resources.
Air-Surface Exchange of Persistent Organic Pollutants in North America
Keywords: persistent organic pollutants
soils
air
enantiomers
Arctic
Mexico
organochlorine pesticides
bioaccessibility
chemical partitioning space
volatiltiy

This thesis examines the air-soil and air-water gas exchange of persistent organic pollutants (POPs) with emphasis on organochlorine pesticides (OCPs). The current status of net exchange, factors which influence the exchange process, and different approaches used to estimate the surface exchange were explored. The net exchange of chemicals was evaluated using the fugacity approach, with the aid of chemical tracers (congener profiles of complex mixtures and enantiomer proportions of chiral chemicals) to infer current use vs. legacy sources to the atmosphere. DDT in southern Mexico was undergoing net deposition from air to soil. Occurrence of fresher DDT residues in the south was indicated by a higher proportion of p,p’-DDT relative to p,p’-DDE and racemic o,p’-DDT in air and soils. Congener profiles of toxaphene suggested soil emissions as the source to air. The influence of chemical aging on soil-air exchange and bioaccessibility was studied in a high organic soil. The use of nonexhaustive extraction with hydroxypropyl-beta-cyclodextrin (HPCD) to predict bioaccessibility was optimized for OCPs and polychlorinated biphenyls (PCBs). Reduced volatility of spiked chemicals correlated with reduced HPCD extractability for soil that had been aged under indoor and outdoor conditions for 730 d and infers volatility could be used as a surrogate for bioaccessibility. Measured soil-air partition coefficients (Ksa) were lower than those predicted from the Karickhoff relationship, which considers octanol as a surrogate for soil organic matter. The role of soil moisture, organic carbon, temperature, depth of soil surface horizon and dissolved organic carbon in the fate of organic contaminants in soil were assessed using chemical partitioning space maps. These maps allow instant visual prediction of the phase distribution and transport process of a chemical among the three major phases in soil; i.e., air, water and solid. Net volatilization of alpha-hexachlorocyclohexane from water to air was found in the southern Beaufort Sea using fugacity calculations and flux measurements. The influence of ice cover on volatilization was indicated by a winter-summer shift from racemic to nonracemic alpha-HCH in boundary layer air.
Structural and Functional Regulation of the Human Chloride/Proton ClC-5 by ATP and Scaffold NHERF2 Interactions
Keywords: ClC-5
CBS Domains
ATP Binding Site
NHERF2
SAXS
Thermal Stability
Photoaffinity Labelling
Endocytosis
Internal PDZ Binding Motifs

The chloride/proton antiporter ClC-5 is primarily expressed in the kidney where it aids in re-absorption of proteins from the glomerular filtrate. Functional disruption of ClC-5 causes Dent’s Disease – a renal condition characterized by proteinuria and kidney failure in a third of all cases. The majority of disease-causing mutations translate into premature truncations of the carboxy-terminal (Ct) region of ClC-5 and are predicted to disrupt the protein-protein interactions mediated by this domain. In this thesis, direct ATP binding to the two cystathionine β-synthase (CBS) domains of ClC-5 was demonstrated. ATP binding enhanced the global compactness of the ClC-5 Ct region likely through a clamping motion of the CBS domains around the nucleotide. Along with ATP, the sodium proton exchange regulatory factor 2 (NHERF2) also binds ClC-5; however, the molecular mechanism behind this interaction was unknown as ClC-5 lacked the PDZ binding motif traditionally localized at the Ct end of bait proteins. Here, we also identified a class I PDZ binding motif (657-660; TSII) within the internal sequence of ClC-5. Despite the buried position of this motif in the Ct peptide’s X-ray crystal structure (PDB: 2J9L), the high propensity of this region for dynamic flexibility prompted us to test whether it could mediate NHERF2 interactions. In support of this hypothesis, we demonstrated that the motif is transiently available to interact directly with NHERF2 in vivo and to enable an enhancement in receptor-mediated endocytosis in mammalian cells. Collectively, these results gave further evidence that the intracellular Ct region of ClC-5 serves as a hub to mediate interactions essential for its maturation, stability, and trafficking in renal epithelium, as well as providing further insights into the molecular basis of Dent’s Disease.
Identification and Characterization of Cancer Stem Cells in Mouse Medulloblastoma and Glioma
Keywords: Medulloblastoma
Glioma
Cancer Stem Cell
Mouse Model

According to the cancer stem cell hypothesis a subpopulation of cells within a tumour has the capacity to sustain its growth. These cells are termed cancer stem cells, and are most simply defined as the cells within a primary tumour that can self-renew, differentiate and regenerate a phenocopy of that cancer when transplanted in vivo. Cancer stem cells have now been prospectively identified from numerous human tumours and are actively sought in many cancer types, both clinical and experimental. The cancer stem cell hypothesis remains controversial, with evidence both supporting and challenging its existence in human tumours and in animal models of disease. Here we prospectively identify and study brain cancer stem cells in clinically representative mouse models of the medulloblastoma and glioma. Cancer stem cells from both mouse brain tumour types are prospectively enriched by fluorescent activated cell sorting freshly dissociated cells for the surface antigen CD15, display a neural precursor phenotype, exhibit the hallmark stem cell characteristics of self-renewal and multilineage differentiation, and regenerate a phenocopy of the original tumour after orthotopic transplantation. Additionally, novel mouse medulloblastoma and glioma cancer stem cell lines were established and studied in vitro as adherent cultures in the same serum-free media conditions that support the growth of normal neural stem cells. When mouse and human glioma stem cell lines were compared, many novel molecular mediators of the tumour phenotype were identified, as were chemical compounds that selectively inhibit their growth. Our results have important implications regarding the cancer stem cell hypothesis, the mechanisms that drive brain tumour stem cell growth and the therapeutic strategies that may prove effective for the treatment of glioma and medulloblastoma.
A Review of Transformational Leadership Research: A Meta-analytic Approach
Keywords: School Leadership
Meta-analysis
transformational leadership
review

This research is a meta-analytic review of the effects of transformational school leadership (TSL)-- a systematic, comprehensive synthesis of the quantitative research on transformational school leadership. The review method used in this research is standard meta-analysis supplemented by narrative synthesis and vote-counting methods. The types of effect sizes involved in meta-analytical calculations are correlation coefficients rs. The evidence reviewed was provided exclusively by unpublished theses or dissertations that were completed between 1996 and 2008. This study identified 33 dimensions of transformational leadership as developed by various scholars and captured by a variety of leadership measures, which were synthesized into 11 core leadership dimensions. This study meta-analyzed the effects of transformational school leadership and its dimensions on a large range of school outcomes, including 17 school conditions (e.g., school culture, shared decision-making processes), 23 teacher-related outcomes (e.g., teacher satisfaction), and five types of student outcomes. Transformational school leadership was most influential on teachers’ emotions and inner states. TSL had large effects on teachers’ individual inner states and their practices while it had small effects on their group inner states. Leaders effectively influence teachers’ psychological inner states and practices mainly through modeling good practices themselves, providing support and intellectual stimulation to teachers individually and setting shared school goals. TSL was also very influential on school conditions. It had large effects on four key school conditions. This review detected significant, positive small direct effects of TSL on student achievements. The indirect effects of TSL on student learning vary when different school or teacher variables are controlled. This review identified seven important moderators and three mediators that significantly contributed to student learning along with TSL. Specific leadership practices that effectively influenced school and student outcomes were also examined and discussed. Regarding the moderating effects of contextual and methodological factors, school level and leadership measures were found to moderate leadership impacts significantly in some cases. The findings of this study provide guidance for school administrators and policy makers who want to improve school leadership as a means of improving school quality.
From Elusive Conceptions to Arrested Developments: Leadership for Social Justice
Keywords: educational administration
leadership

The general question guiding this research is: how do equity minded administrators lead for social justice? The following specific questions are addressed in this study: How have participants become oriented to social justice? How do educational administrators conceptualize leadership for social justice? What are the barriers and supports that participants experienced in leading for social justice in diverse contexts? What are some (participant-identified) examples of how they lead for social justice? From a critical perspective this study examines the experiences of educational administrators leading for social justice. Vital to this examination are analyses of power relations and the locatedness of participants within those relations. At the core of these power relations are participant experiences of social justice as contingent on the interconnectedness between their lived realities and the “doing” of social justice as espoused by and evidenced in their approaches to leadership for social justice. For this study I have interviewed ten administrators from Southern Ontario, who self-identify as being committed to and leading for social justice and have been in formal positions of leadership for at least five years. Interviewees were able to identify and articulate the interconnected experiences of lived realities and their commitments to leadership for social justice; critical examples of social justice praxis; and facets of the educational systems which supported and, conversely, erected barriers to their leading for social justice. Conclusions, implications and recommendations can be broadly organized as issues related to systemic and structural processes, support and accountability for the hiring, retention and promotion of diverse school personnel who have evidenced commitments to social justice, the retraining and retooling of educators and leaders through curriculum centred on social justice, the dramatic restructuring of educational administrative thought by practitioners and researchers, and the critical inclusion of the community, students, parents and trustees in roles that substantively impact the decision making power within the educational system (from the overall governance of the educational system to everyday activities).