VictorJuiz/thesis huggingface dataset:
The role of the prohormone convertases in the post-translational processing of intestinal proglucagon

Proglucagon (proG) is post-translationally processed in a tissue-specific manner to yield glucagon in the A cells of the pancreas, and glicentin, oxyntomodulin, glucagon-like peptide (GLP)-1 and -2 in the L cells of the intestine. Each of the constituent peptides of proG is flanked by pairs of basic amino acids, which are known sites for prohormone cleavage. The identification of the prohormone convertase (PC) family of processing enzymes has facilitated the study of prohormone processing. To determine the roles of PC1 and PC2, and other convertases, in the tissue-specific processing of proG, vaccinia virus (vv)-mediated infection of endocrine-derived cell lines was utilized. GH$\sb3$ and AtT-20 were co-infected with vv:proG plus vv:furin, vv:PC1, or vv:PC2. Cells were also infected with vv:PACE4, vv:PC5a or vv:PC5b alone, or with vv:PC2. PC1 processed proG to glicentin and oxyntomodulin, GLP-1$\sp{\rm 1{-}37/36NH2}$ and GLP-1$\sp{\rm 7{-}37/36NH2}$ and GLP-2. Infection with PC2 alone or in combination with other enzymes resulted in the production of glicentin, but not glucagon. To further confirm these findings, we stably transfected the pancreatic InR1-G9 cell line with PC1 and/or antisense PC2 (ASPC2). Transfection with PC1 increased glicentin, GLP-1$\sp{\rm 1{-}36NH2}$ and GLP-2 production, while a reduction in PC2 attenuated glicentin, but not glucagon, production. Co-regulation of PC1 and proG mRNA in the L cell was examined in an enteroendocrine cell line, GTag-Y. Stimulation of protein kinase A in GTag-Y cells increased secretion of both GLP-1$\sp{\rm 7{-}36NH2}$ and GLP-2, however, neither levels of proG nor PC1 mRNA were increased. Therefore, we were unable to show co-regulation of proG and PC1 due to lack of suitable models. Taken together, these studies establish a role for PC1 in the processing of proG to yield the intestinal peptides, glicentin, oxyntomodulin, GLP-1$\sp{\rm 1{-}36NH2}$ and GLP-2, and suggest that PC2 is responsible for the processing of proG to glicentin, another enzyme being required for the production of glucagon.
Surface thermodynamics and biophysics of the lung

This thesis applies principles and methodologies of surface thermodynamics to problems of lung physiology. In order for the muscular system to be able to perform the work of expansion and compression of the lung, the surface tension must be as low as possible. Nature facilitates this by providing a lung surfactant, consisting of a mixture of lipids and proteins, which are transported and maintained at the surface of the lung. Correct surface tension measurements of such systems have become available only very recently. These measurements have been cumbersome and based on assumptions, the correctness of which could not be guaranteed generally. In order to overcome the current difficulties, a methodology, Axisymmetric Drop Shape Analysis-Captive Bubble (ADSA-CB), was developed for surface tension measurement. This new technique allows mimicking of the periodic inflation and deflation of the lung while measuring thousands of surface tension values in a very short time. With this technique, the so-called "squeeze-out" and film collapse phenomena were examined closely. An important aspect of lung surfactant is the fact that, ultimately, the surface film will be composed almost exclusively of lipids, mostly dipalmitoyl phosphatidyl choline (DPPC). By means of an ADSA study on the DPPC monolayer, a mechanism of lipid arrangement at the surface was proposed: gaseous phase, gradual transition from gaseous to liquid-condensed and to solid phase, and solid phase. To develop expressions for the key performance measures of lungs, such as surface area, distortion energy and mechanical work, in terms of measurable quantities, a thermodynamic model of the lung has been developed: Starting with a general thermodynamic expression for the distortion energy, a relation between the recoil pressure and the surface tension was found. Using the properties of partial derivatives, a general expression for the surface area was derived. For the two separate cases: (1) lungs with constant surface tension and (2) air-filled lungs, explicit expressions for the distortion energy and mechanical work were obtained. The model predictions are in good agreement with the experiment in all situations.
Capital market segmentation, the case of Canada and the United States

This thesis focuses on the issue of capital market segmentation (integration) in the North American market. More specifically, it investigates the existence of partial segmentation between Canadian and U.S. capital markets. Testing specifically for partial segmentation, as opposed to complete segmentation, is important because failure to do so could lead to inappropriate inference. To test for partial segmentation, I first examine the factors that potentially segment the North American market. It is suggested that factors associated with a firm's listing status, firm size, and dividend yield are likely to contribute to the segmentation of Canadian and U.S. markets. Using these instruments (listing status, firm size and dividend yield), I partition the overall sample of Canadian firms into sub-groups which are then used to test the hypothesis of partial segmentation. The tests are run over different time periods, using a univariate and a multivariate framework. I also run a number of sensitivity tests. For instance, I test for different definitions of interlisted firms, the impact of thin trading in Canadian stocks, and the impact of outliers. The results show that listing status plays a role in the segmentation of Canadian and U.S. markets. More specifically, we find more evidence of integration for the interlisted firms than we do for purely domestic stocks. However, the results also show that both firm size and dividend yield are useful in controlling for the factors segmenting the North American market. In particular, the results provide support for the hypothesis that small (large) Canadian firms are more likely to be priced in a segmented (integrated) market. Similarly, controlling for size, high (low) dividend yield firms are more likely to be priced in a segmented (integrated) North American market. Thus, the results suggest that differential taxacion between Canada and the U.S. and factors related to firm size such as information incompleteness contribute to the segmentation of the North American market. Finally, it is interesting to note that our results help explain why existing studies provide conflicting evidence as to the existence of segmentation in the North American market.
Chinese-Canadian attitudes toward end of life decisions

Purpose. The purpose of this study is to examine Chinese Canadian attitudes toward end of life decisions. While extensive information is available on attitudes towards end of life decisions in general, little is known about attitudes of specific cultural communities. Within Western health care, autonomy is the dominant value on which the intellectual and moral foundation of end of life decisions are based. At the heart of this value is the belief that everyone is entitled to free choice, self determination, and privacy. Vet for many people of non-Western origin the image of the self is based on his or her relations with others rather than individual free will. A Chinese sample has been selected because of the contrast this group represents in relation to an autonomy based perspective and because of the demographic significance of the Chinese in Canadian society. Methods. Three elements of end of life decisions are explored in this research project: (a) advance care planning, (b) truth telling, and (c) decisions to forgo treatment. Because of the complexity of phenomena at the intersection of attitudes toward end of life decisions in relation to culture, this research project is an ethnographic, qualitative study. The constant comparison method was used for analysis. Results. (a) respondents were indifferent or negatively disposed to advance care planning; (b) respondents perceived truth telling to be variable in its importance, potentially harmful, and a "process" rather than an "event"; (c) in relation to decisions to forgo treatment, respondents were focused on the importance of avoiding or alleviating suffering for the patient and others affected by the illness and minimizing burdens to the family, the health care system, and the government. Conclusion. From a moral and ethical perspective respondents' attitudes represent a 'world view' which deals with a concrete situation and focuses on such values as interdependence, comparison and protection in contrast to an autonomy based 'world view' which deals with abstract and hypothetical situations, and focuses on such values as individualism, self determination and rights. For respondents in this study, moral perspective appeared to reveal itself through context rather than universal principles.
Endocrine factors and risk of testicular germ cell cancer

A population-based case-control study was conducted in the province of Ontario to examine the relationship between prenatal and pubertal endocrine exposure on the risk of testicular germ cell cancer. Cases included males aged 16 to 59 with a diagnosis of testicular germ cell cancer between 1987 and 1989. Controls were a population-based random sample frequency matched by 5-year age groups. Data were collected on 502 cases and 346 case mothers and 975 controls and 522 control mothers using a self-administered questionnaire to subjects and a phone interview to mothers. A number of prenatal and perinatal exposures were found to be statistically significantly associated with risk of testicular germ cell cancer. Risk was elevated for in-utero exposure to exogenous hormones (i.e. prescription hormones including diethylstilbestrol (DES), injections and pills to determine pregnancy and birth control pills); mothers' cessation of birth control pill use within 3 months of conception; and preterm birth (delivery more than two weeks earlier than expected). Risk was decreased for heavy (12+ cigarettes per day) maternal smoking; young ($<$20 years) maternal age; and bleeding and threatened miscarriage. In addition, this study reports a protective effect from later puberty. These risk factors are discussed with respect to the hypothesis that endocrine exposures are associated with risk of testicular germ cell cancer.
Explicating expectations of faculty and students in the professional education of physiotherapy

The focus of my research was directed at explicating the expectations of faculty and students as they relate to Physiotherapy education. The scope of expectation involved perceptions of the faculty and students as to various educational elements of the Physiotherapy training. My research was conducted over a four year period between 1987 and 1990, and included three subsequent Physiotherapy classes and the Physiotherapy Faculty at an Ontario Community College. Students and faculty were asked to respond to questions pertaining to their expectations of (a) program design, (b) design of instruction, (c) elements of student learning, and (d) professional issues. The method used to explicate faculty and student expectation involved a matching of responses to questions focusing on aspects of the same academic element. The results of the study indicated that students and faculty had inaccurate expectations in terms of the same academic issues. Both students and faculty underestimated the level of adaptation which was necessary for students to adjust to the demands of the educational environment. Students had inaccurate expectations of themselves in terms of their ability to process theoretical information and apply theory to practical application. Students also had inaccurate expectation as to their potential for success and positive adaptation to the educational environment. Faculty had inaccurate expectations of student ability and the effectiveness of the curriculum and instructional design to develop clinical competence and performance in students. There were also instances where the structure of the academic program did not support the expectations of both faculty and students in terms of supporting teaching and learning initiatives. Explicit communication of student, instructional and professional expectations, plus the provision of a mechanism for formative feedback amongst students and faculty would allow for a more positive adaptation to academic and professional demands.
Analog Viterbi detection for partial-response signaling

Along with the growth of signal processing capabilities, sequence detection of digital signals transmitted over noisy channels has become the preferred choice in many applications. Consequently, researchers accelerated their efforts toward addressing the implementation issues of such detectors. Naturally, almost all of the solutions were developed in a digital realization environment, mainly because digital signal processing has been shown to be powerful and flexible. At the same time, the idea of analog implementations of sequence detectors was introduced by a small dedicated minority in the hope of finding areas where digital solutions fail to fulfill some of the system requirements. This hope became a reality when analog Viterbi decoders outperformed their digital counterparts in the exceptionally demanding saturated magnetic storage application. The challenge was to realize the Viterbi algorithm such that the ever increasing requirements of small size, low power, and high speed are satisfied. Described in this thesis, is another attempt for realizing the Viterbi algorithm in the analog domain. Partial-response sequence detectors with application to magnetic recording and data transmission over cables are of special interest, however, other subjects are also addressed. Although the essence of an analog realization is to eliminate the power-hungry analog-to-digital converter, here it is shown that additional savings may also be accomplished if the algorithm is carefully examined from an analog implementation perspective. In particular, in this thesis, an analog architecture for realizing a class-IV partial-response Viterbi decoder is introduced, integrated circuit implementation of this decoder is described, and experimental results are presented. The operating speed and savings in the silicon and power consumption are well beyond the reach of any reported digital decoder, even in more advanced technologies in many cases. Furthermore, and supported by experiments, it is shown that more complicated signaling schemes can also benefit from an analog implementation. The idea was to alleviate the transistor-level obstacles and encourage analog designers to explore new territories for analog sequence detectors. Finally, some implementation issues of reduced-state sequence decoders are addressed and analog solutions are introduced.
An Examination and Critique of the Contract Model of Legal Regulation of Preconception Arrangements and an Alternative Proposal for Law Reform in Ontario

This dissertation examines the practice of preconception arrangements ("surrogate motherhood") and the central arguments for its legal permissibility to determine how Ontario ought to respond. It claims that the major arguments for the practice from autonomy, equality, welfare maximization and suffering minimization are flawed because, inter alia, they fail to demonstrate the practice achieves these alleged beneficial consequences. Further, the contract model which they advocate is an inapplicable and inappropriate form of legal regulation because, when used in this context of human procreation, it would cause harm to participants and non-participants and to society generally, and it would violate five important ethical principles--autonomy, equality, welfare maximization, suffering minimization and responsible parenthood. The dissertation's claims are advanced in nine ways: (1) The common description of the practice is made more complete and accurate by reference to demographic studies and personal accounts. (2) The arguments of six proponents (John Robertson, Lori Andrews, Richard Posner, Michael Trebilcock, the Ontario Law Reform Commission and the American Fertility Society) are demonstrated to be unconvincing, (3) to rely on an incomplete characterization of persons, and (4) to be based on ideologies of patriarchy, technology and commodification (5) all of which result in flaws of analysis. (6) The contract model advanced by proponents is revealed as inapplicable because the expectation interest it seeks to create is either incapable or unworthy of legal protection, and as (7) inappropriate because of its harmful consequences. (8) Thus, when the contract model is used to regulate preconception arrangements, the practice entails the sale or waiver of reproductive rights; capitalizes on gender, class and race inequality; causes the break-up of families; transfers the pain of childlessness from one person to another; and aims to prevent the development of relationships between mother and child, and mother and father, presenting serious obstacles to the exercise of responsible parenthood. (9) The dissertation concludes that as a social practice of human procreation which, when regulated by contract law, has harmful results, preconception arrangements ought to be governed by family law, and more specifically, by the proposed legislation recommended herein.
Microstructures and Mechanical Properties of Nanocrystalline Materials

The effect of grain size (in the grain size range of 6-40 nm) on the mechanical properties of polycrystalline materials was investigated using bulk (40 x 10 x 0.2 $\sim$ 0.3 mm) nanocrystalline nickel electrodeposits produced by the pulse plating technique. Microstructures of the materials were characterized using X-ray diffraction and electron microscopy. It is found that (1) the nanocrystals in the materials are equiaxed in shape and follow the log-normal distribution, (2) the intercrystalline regions in nanocrystalline materials are highly strained compared to the conventional polycrystalline counterparts. Unidirectional tensile tests were performed to get the stress-strain curves from which the flow stresses were obtained. Deviation from the Hall-Petch relationship was observed and interpreted in terms of dislocation behaviour in nanocrystals and a composite model that is developed based on the volume fraction analysis of the intercrystalline components. The deformation mechanisms of nanocrystalline materials were further studied through a series of creep tests. It is found that diffusional creep controlled by grain boundary sliding is the major deformation mechanism for nanocrystalline nickel electrodeposits with grain sizes smaller than 40 nm and the contribution of triple line diffusion can be significant for smaller grain sizes. DSC measurements have further confirmed the active diffusion process in nanocrystalline nickel electrodeposits. An analytical expression of the contribution from the triple line diffusion has been derived and introduced into the apparent diffusion coefficient in the power law relation for the creep rate. The analysis of strain rate sensitivity suggested that dynamic creep should be taken into account when analyzing the stress-strain curves of nanocrystalline materials. The constitutive equation of stress-strain relation due to dynamic creep has been derived under the condition of constant loading rate.
In Search of a Protein Nucleator of Hydroxyapatite in Bone

The formation of mineralized connective tissues is characterized by the nucleation of hydroxyapatite crystals that are generated initially within the gap region of collagen fibrils. However, the mechanism of mineral nucleation has not been resolved. It is believed that a heterogenous (epitactic) nucleator is likely required to provide a template for the crystal lattice. Consistent with the location of the mineral crystals a nucleator is envisaged as being a collagen-binding protein with the ability to bind to calcium and hydroxyapatite. Thus, it by isolating proteins from newly-forming bone tissues according to their affinity for collagen and hydroxyapatite the subsequent identification and thesis an characterization of the mineral nucleator could be facilitated. To test this hypothesis an extraction procedure was developed in which guanidine hydrochloride (GuHCl) and ethylenediaminetetra-acetic acid (EDTA) were used to sequentially solubilize proteins from fetal porcine bone. Initial extractions of the bone with 4 M GuHCl released proteins that were associated with the osteoid/soft tissue matrix. Subsequent extractions with 0.5 M EDTA demineralized the bone and released mineral-bound proteins, included osteonectin, decorin, osteopontin, bone sialoprotein, small collagenous apatite-binding proteins and a novel chondroitin sulfate proteoglycan (CS-PG III), which were purified for further characterization. Initial studies were focused on osteonectin since it had been proposed as a potential nucleator. However, studies of osteonectin biosynthesis, tissue distribution and physicochemical characteristics revealed properties that were inconsistent with a bona fide nucleator. Consequently, studies were then directed at proteins dissociatively extracted from the de-mineralized collagen matrix with 4 M GuHCl. Two apparently unique 32 kDa and 24 kDa proteins were purified and identified as lysyl oxidase and tyrosine rich acidic matrix protein (TRAMP). Since these proteins did not have the characteristics of a nucleator, the tissue residue was digested with CNBr to identify proteins tightly bound to the demineralized collagen matrix. Although a protein nucleator was not identified in these studies, the development of a selective extraction procedure and protein purification protocols facilitated the characterization of the major proteins in fetal porcine bone. Many of these proteins are likely to be involved in the formation, growth and stabilization of hydroxyapatite crystals.
Mechanistic Modelling of the Elmendorf Tear Energy of Paper

In this study, a mechanistic model was developed for the Elmendorf tear energy of paper based on the fundamental physics of the tear process. In the model, the tearing energy was calculated as the sum of fibre fracture energy and fibre pull-out energy since both energies were found to be significant in a series of single fibre pull-out experiments. The model also included statistical considerations, such as the distribution of fibre lengths. Through dimensional analysis, a "dimensionless tear index" was identified and was found to be a universal function of three dimensionless parameters: $\alpha,\ \beta$ and $\epsilon .\ \alpha$ is fibre strain and $\beta$ is equal to the ratio of frictional resistance to the debond force. $\epsilon$ is proportional to the ratio of fibre length to the critical length and depends on the bond strength and sheet density for a given furnish. When the dimensionless tear index was plotted against $\epsilon$ at given $\alpha$ and $\beta ,$ almost all of the tear index data used to test the model fit on a single curve. This universal plot of the dimensionless tear index versus dimensionless bonding was divided into three regions. Simple approximation equations for these regions can be used to give rough estimates of the tear energy, based on a few measurements of fibre and paper structure. Using a bond strength obtained through non-linear regression analyses on a particular experimental data set, the model was validated with other sets of data. It was found that the model gave good quantitative predictions of tear energy without the need for adjustable fitting parameters. With a slight modification to account for the role of fines in the furnish, the model was also successfully applied to handsheets made by artificially blending fibres and high specific surface area fines of mechanical pulps.