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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

The Effects of Migration Selectivity on Quebec's Population

Caldwell, Kim 04 1900 (has links)
<p> The issue of preserving Quebec's French culture has become paramount to those who fear its future existence. Maintaining a large proportion of the Canadian population is necessary in order for cultural preservation. However, Quebec is losing its share of the national population, despite the introduction of various policies to increase that proportion. </p> <p> The purpose of this research is to study the effects of migration selectivity, that is, the differences in migration behaviour with respect to personal attributes, on Quebec's population. The personal attributes considered are birth place, education level, marital status, mother tongue and gender. For each personal attribute, the net migration rate is determined for 10 different age groups. The net flow of people across the Quebec border will then be revealed. The characterization of the people who are migrating in and out of Quebec will be established and finally the ultimate effect the migration process has on the Quebec population will be discussed. </p> / Thesis / Candidate in Philosophy
32

Theoretical Studies Of II-Facial Selectivity In Sterically Unbiased Systems

Kalyanaraman, P 09 1900 (has links) (PDF)
No description available.
33

Kritérium selektivity v oblasti státní pomoci ve světle judikatury SDEU / The selectivity criterion in the field of State aid in the light of the ECJ's case-law

Hlista, Jakub January 2016 (has links)
The selectivity criterion is one of the defining elements of State aid within the meaning of Article 107(1) TFEU. The selectivity criterion is considered to be the most important and the most problematic in its application in the assessment of Member States' measures at the same time. The aim of this work is to analyze the development of ECJ's case-law and the Commission's decisional practice related to the selectivity criterion and by means of their analysis to point out the disputableness and lack of clarity of the selecivity criterion and to critically assess the unpredictability and questionable character of certain judgments of the ECJ. The first chapter deals with an introduction to the issue of State aid, subsumes it under the system of competition and describes the defining elements of State aid. The second chapter analyzes one of the two features, into which the selectivity criterion divides, referred to as an advantage. It describes both the broad concept of advantage and also a way how to identify an advantage. It also addresses the exceptions and specific regimes to which the provisions on State aid in principle do not apply. The third chapter considers general issues relating to the second feature of the selectivity criterion, which is selectivity (in the strict sense). It also pays...
34

The neural basis of attention bias toward mood-congruent information in people with major depressive disorder

Leung, Kwok-keung., 梁國強. January 2008 (has links)
published_or_final_version / Psychology / Doctoral / Doctor of Philosophy
35

Selection of transthyretin amyloid inhibitors

Iakovleva, Irina January 2016 (has links)
Amyloidosis is a group of clinical disorders caused by the aggregation of specific proteins into abnormal extracellular deposits. Today, 31 different proteins have been linked to amyloid diseases including transthyretin-related amyloidosis (ATTR). ATTR occurs through the aggregation of either wild-type plasma protein transthyretin (TTR) or a mutated form. TTR is a homotetramer that under normal circumstances functions as a carrier of thyroxine and retinol binding protein. The aggregation cascade requires dissociation of the tetramer into monomers, and preventing this dissociation represents a potential mode of intervention. Interestingly, small molecules, referred as kinetic stabilizers, can bind to TTR’s thyroxine-binding site (TBS) and such molecules are currently being used as a therapeutic approach to impair tetramer dissociation. The efficacy of TTR stabilization is directly correlated to the binding affinity of the ligand to TBS. However, the binding of the ligand to TTR in vivo can be affected by other plasma components resulting in poor efficacy. Thus, the selectivity of ligands is an important parameter. We have designed an assay where the ability to stabilize TTR can be directly evaluated in plasma and we have investigated the stabilizing effect of nine potential TTR binders (Paper I). The results, surprisingly, revealed that the binding affinity of molecules has a poor correlation to its selectivity. However, the nature of protein-ligand complex formation can also be described by enthalpic (∆H) and entropic (∆S) energy contributions. ∆H represents the change in chemical bonds and frequently requires a higher order of orientation compared to the ∆S component, which mainly represents the hydrophobic effect via the exclusion of water. We hypothesized that ligands possessing high ΔH in binding to their co-partner would also be more specific in a complex environment such as plasma. By applying a thermodynamic analysis using isothermal titration calorimetry, we found that the selectivity in plasma correlates well with the ∆H contribution and might, therefore, be a better predictor for selectivity. Luteolin was found to be a highly selective stabilizer of TTR and was investigated further (Paper II). The ligand displayed a significant rescuing effect in both cell culture and animal models. However, luteolin undergoes rapid enzymatic degradation in the liver and this impairs its use as a potential therapeutic drug. To attempt to circumvent this issue, we modified the most exposed hydroxyl group thus rendering the molecule inert towards glucuronidation (Paper III). The substitutions resulted in higher stability in the face of hepatic degradation molecules, but they also affected the selectivity in a negative manner. The screening for new TTR stabilizers resulted in the discovery of tetrabromobisphenol A, which displayed a very high selectivity (Paper IV). This study also included a comparison with the drug Vyndaqel™ which currently is in clinically use, and showed how the dosage could be altered to acquire a better level of saturation and possibly also a better clinical effect. Taken together we present new molecules with the ability to stabilize TTR, and these can serve as scaffolds for the design of new drugs. We present a method to measure the efficacy of a TTR-stabilizing drugs in a complex matrix and as well as a way to adjust the dosage of existing drugs. We also show that the selectivity of a drug is affected by the relative proportion of ∆H and ∆S, and this is of interest for drug design in general.
36

Poptávka českých domácností po potravinách: Koherentní poptávkový systém uvažující selektivitu / Household food demand in the Czech Republic: coherent demand system dealing with selectivity

Smutná, Šarlota January 2016 (has links)
Demand for food is widely studied topic in applied econometrics. Demand systems are the most useful models to evaluate demand and estimate the income and price elasticities. Different demand systems used for food demand are discussed in this thesis. Almost Ideal Demand System (AIDS) is the most popular among researchers thanks to conformity with economic theory, simple estimation, and flexibility with respect to non-linearity of Engel's curves or to control for socio-demographic or structural variables of household. Reporting of zero consumption by respondents when analysing demand on budget survey data requires special treatment, as censoring leads to the selectivity problem and hence biased estimates. Several techniques to treat the selectivity in order to obtain unbiased estimate of demand elasticities are discussed. Specifically, the Heien and Wessels, Shonkwiler and Yen, and Cosslett's semi-parametric corrections are incorporated into the AIDS model and empirically compared among each other. Since homogeneity and symmetry conditions are not fulfilled in this case, income and price elasticities of food demand are estimated by the unrestricted version of QUAIDS model which suits the budget survey data of Czech households the best with the correction for the selectivity by Shonkwiler and Yen's estimator....
37

Scaffolding Catalysis: Towards Regioselective Hydroformylation of Alkenes and Site-Selective Functionalization of Polyhydroxylated Molecules

Sun, Xixi January 2013 (has links)
Thesis advisor: Kian L. Tan / Chapter 1. We reported the first synthesis of all-carbon quaternary centers via hydroformylations using a catalytic directing group. With the ability of reversibly and covalently binding to a substrate, and coordinating to a metal center, scaffolding catalyst 1.1 is able to direct the branch-selective hydroformylation of 1,1-disubstituted olefins under mild temperature. Chapter 2. We have designed and synthesized a chiral organocatalyst 2.11. This catalyst is able to covalently bind to one hydroxyl, and utilize the induced intramolecularity to stereoselectively functionalize the other hydroxyl within a cis-1,2-diol via electrophile transfer. Catalyst 2.11 was used in the desymmetrization of meso-1,2-diols under mild conditions (4 C to room temperature), leading to high yields and selectivities for a broad substrate scope. Chapter 3. Catalyst 3.1 and 3.6 were demonstrated to selectively bind to primary hydroxyls over secondary hydroxyls. By combining the binding selectivity with asymmetric catalysis, these scaffolding catalysts were shown to promote the selective silylation of secondary hydroxyls within terminal (S)-1,2-diols. The reversal of substrate bias was further applied to a regiodivergent kinetic resolution of racemic terminal 1,2-diols, producing secondary protected products in synthetically practical levels of enantioselectivity (>95:5 er) and yields (≥40%). Time course studies of this reaction further revealed the optimal condition to form the primary silylated product in high s-factor. Chapter 4. Based on the previous understanding of catalyst 4.5 and 4.6, the exclusive catalyst recognition of cis-1,2-diols within polyhydroxylated molecules was further discovered. This unique functional group display recognition was further allied with the catalyst's ability to stereoselectively differentiate hydroxyls within cis-1,2-diols, enabling the site-selective protection, functionalization, and activation of the inherently less reactive axial hydroxyl groups within carbohydrates. This methodology also enables the selective functionalization of multiple complex molecules, including digoxin, mupirocin, and ribonucleosides, demonstrating the potential power of scaffolding catalysis in the rapid access to valuable synthetic derivatives of polyhydroxylated compounds. / Thesis (PhD) — Boston College, 2013. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.
38

Attentional bias in depression and anxiety: a negative priming paradigm.

January 2006 (has links)
Yau Wai Fun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 66-76). / Abstracts in English and Chinese. / ABSTRACT (English) --- p.ii / ABSTRACT (Chinese) --- p.iv / ACKNOWLEDGEMENTS --- p.v / TABLE OF CONTENTS --- p.vi / LIST OF TABLES --- p.viii / LIST OF FIGURES --- p.ix / LIST OF APPENDICES --- p.x / Chapter CHAPTER ONE - --- Introduction --- p.1 / Models of Information Processing / Empirical Evidences For and Against Attentional Bias / Model of Attention and Selective Attention / Issues of Methodology / The Present Study / Chapter CHAPTER TWO - --- Method --- p.34 / Participants / Self-Report Measures / Apparatus and Stimuli / Procedure / Chapter CHAPTER THREE - --- Results --- p.44 / Effect of Experimental Manipulation / Priming Effect and Attentional Bias / Emotional versus Neutral Target Stimuli / Group Difference / Chapter CHAPTER FOUR - --- Discussion --- p.54 / "Stimuli, Priming Effect, Attentional Bias, and Psychopathologies" / Methodology and Attentional Bias / Limitations and Further Studies / Conclusion / REFERENCES --- p.66 / APPENDICES --- p.77
39

Fresh Approach for High-Throughput Studies of Ion-Selective Materials Using Reusable ChemFET Platform

Banning, Douglas 30 April 2019 (has links)
Aqueous anions play an important role in our world, and the ability to continuously measure them provides both environmental and health benefits. Chemically-sensitive field effect transistors (ChemFETs) are becoming increasingly popular in the field of aqueous measurement due to their relatively low-cost capability for real-time, continuous sensing. Receptor molecules or mixtures displaying affinity for a particular ion can also be utilized in a ChemFET gate membrane. Receptors can be incorporated into the gate oxide membrane and the entire ChemFET can utilized in an aqueous environment, thus utilizing hydrophobic receptors in an aqueous anion-sensing application. Demonstrating the ability to reuse the sensors validates an important characteristic for ChemFET-based research. Additionally, numerous other receptor molecules are evaluated against an array of common anions. Selectivity coefficients are compared to the Hofmeister Series. Additional membranes are evaluated for suitability for incorporation of receptors on the ChemFET gate oxide surface. This thesis includes previously unpublished co-authored material. / 2021-04-30
40

Investigations of self-sufficient P450cam monooxygenases for activity and enantioselectivity

Eichler, Anja January 2016 (has links)
Catalytic, selective C-H bond activation for the oxidative hydroxylation RH → ROH of simple or complex compounds is of significant interest in synthetic organic chemistry. One of the major classes of enzymes used for C-H bond activation are cytochrome P450 monooxygenases (EC 1.14.X.X), which can promote chemo-, regio- and stereoselective oxidations under mild reaction conditions. For the current study, catalytically self-sufficient forms of biocatalyst P450cam-RhFRed were investigated. These self-sufficient P450 systems were previously created by fusing the reductase domain of P450 RhF (CYP116B2, RhFRed from Rhodococcus sp.) with the catalytic domain of P450cam (CYP101A1, Pseudomonas putida), thus mimicking the natural fusion of P450 RhF. The generation of 93 P450cam-RhFRed variants has expanded the synthetic toolbox to serve as a basis for exploring the substrate scope towards ethylbenzenes, substituted alkylbenzenes, 4-ethylphenol and (+)-pleuromutilin. To select for active mutants from this library of 93, high throughput screening methods were developed. A pooling approach was applied in order to express P450s and analyse them against a panel of non-natural substrates, such as ethylbenzene, 4-ethylphenol and (+)-pleuromutilin in whole cell biotransformation reactions. The concentration of P450 enzymes was determined using CO difference spectroscopy in whole cells. The assay was significantly improved both in terms of speed and safety by using carbon monoxide releasing molecules as a source of CO rather than the gas CO itself. These screening studies served as starting point to identify P450cam-RhFRed mutants for specific reactions. In particular, a systematic investigation of this library showed mutants that generated chiral benzyl alcohols with good enantioselectivities. To interpret these results on a structural basis, molecular dynamics simulations were used to estimate enantioselectivity of selected mutants for the regio-isomers of methylated ethylbenzene derivatives. The results from the molecular dynamics simulations were broadly consistent with experimentally determined data and identified the importance of conformational changes and flexibility of mutant-substrate complexes to enforce enantioselectivity.

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