VictorJuiz/thesis huggingface dataset:
Activity Regulation of Murine SHP-1

Elucidation of the physiological function of an enzyme requires an intimate knowledge of (1) the enzyme's catalytic reaction, (2) the enzyme's substrates and the products generated, (3) how its products affect cellular processes, and (4) how the activity of this enzyme is regulated. SHP-1 is a SH2-containing protein tyrosine phosphatase (PTPase). It removes phosphate groups from a myriad of proteins, some of which are cell surface signaling receptors. In general, this enzymatic reaction inactivates a signaling cascade that began with the binding of a signaling receptor to its ligand. Regulation of the activity of SHP-1 occurs at several levels which include post-translational modification, subcellular translocation, transcriptional regulation, and SH2-mediated autoregulation. These latter two modes of regulation are not well defined for SHP-1. First, the mechanism and the motifs responsible for the SH2-mediated inhibition of the PTPase are not well defined. Second, we identified a series of alternative transcripts, all maintaining the original reading frame, that omit exons which encode various portions of the SH2 domains of SHP-1. As such products are expected to have altered autoregulatory properties and thus might constitute a mechanism utilized by cells to regulate the activity of SHP-1, it is important to assess whether these transcripts are translated in cells. To this end, I investigated whether the protein products of some of these transcripts are present in cells. I also generated recombinant protein in bacteria using these alternative transcripts and performed enzyme kinetic analyses to assess whether these isoforms indeed have altered autoregulatory properties and to map the motifs that are responsible for autoregulation.
Implicit/explicit learning of focus marking in Japanese as a foreign language: A case of learning through output and negative feedback

This dissertation investigates effects of output and negative feedback (NF) on the learning of a conceptually complex target language domain: the morphosyntactic marking of focus using the particle 'ga' in argument-focus identificational sentences. Research in cognitive psychology and linguistics suggests that output and NF that makes use of metalinguistic explanation help second language (L2) learners to attend to relevant form-meaning relations in the target domain. This hypothesis was tested experimentally. Participants were 52 adult learners of Japanese as a foreign language (JFL) whose first languages (Lls), mostly English and Chinese, do not mark focus morphologically. A computer-assisted L2 learning and testing environment was set up. The experiment was carried out individually in three sessions and lasted for about 20 days. Interventions happened only once, at the beginning of the experiment. Learners' accuracy was tracked during the training and the five tests, and the relationship between their accuracy and certainty was tracked at the beginning and the end of each session. The results of the study demonstrated a clear effect of NF that includes metalinguistic information. NF affected the accuracy of participants' L2 construction, and accuracy in turn affected certainty in their estimate of their answers' correctness. NF appears to increase the salience of the critical features of complex concepts. Explicit learning through such NF is thus argued to have educational benefits for adult L2 learners, and may be necessary for those whose Ll lacks a surface form functionally similar to that of the L2. Output production was also demonstrated to facilitate adult L2 learning of complex concepts, although its effects were slow to emerge. The semantic content of noun phrases (NPs) differentially affected the difficulty of acquiring a syntactic structure that included them: the more typical such NPs are as topic, the more difficult it was for learners to use them as focus elements and to mark them with ga in argument focus sentences. Taken together, these results support the overall pedagogical benefits of explicit learning of complex concepts, especially for learners whose L Is are more likely to cause negative transfer to the L2 and who are in FL learning contexts.
A novel cartilage biochemical marker (CM-1), isolation, purification and characterization

Fluorescent biomolecules within cartilage matrix can be used as specific markers of cartilage metabolism. This thesis originally aimed to investigate changes in articular cartilage (AC) collagen crosslinks associated with maturation, ageing and osteoarthritis (OA). Following hydrochloric acid (HCl) hydrolysis of AC, chromatographic analysis of collagen crosslinks revealed an apparently novel fluorescent compound (Cartilage Marker-1; CM-1), the characterization of which became the focus of the thesis. To isolate CM-1, freeze-dried bovine metacarpophalangeal AC was hydrolyzed in 6M HCl at 110°C for 24 hr. CM-1 was purified by reverse-phase HPLC and its elution was monitored using a fluorescence detector at excitation wavelength, [lambda] = 306 nm, and emission wavelength, [lambda] = 395 nm. From bulk preparations, 12 [mu]g (58 nmol) of CM-1 per gm dried AC was obtained. Purified CM-1 was characterized by mass spectrometry, nuclear magnetic resonance spectroscopy, and single crystal x-ray diffraction. CM-1 is a symmetrical aromatic compound, molecular weight 204, molecular formula C11H8O4, and a molar extinction coefficient 4700 M-1.cm-1 at maximal UV absorption ([lambda] = 306 nm). CM-1 has the IUPAC nomenclature of 2,6-dimethyl-difuro-8-pyrone. CM-1 is a product of HCl hydrolysis of the carbohydrate moiety of cartilage but not cartilage collagen. A protocol was developed to quantify CM-1 in biological compounds and tissues. From preliminary results, CM-1 was detected in all hyaline cartilage and synovial fluids from human and various animal species. As well, CM-1 was detected in reconstituted AC matrix produced 'in vitro'. CM-1 concentration is higher in human neonatal AC (3 day old, 525 pmol/mg dried AC) versus old AC (>53 yr. old-range 182 to 238 pmol/mg). Similar differences were noted in young versus old rabbit cartilage. In human and bovine AC, CM-1 levels were higher in the middle-deep lamina versus superficial-middle lamina. CM-1 in OA cartilage was present in lower amounts (range: 0 to 96 pmol/mg; dried AC) compared to intact AC (range: 63 to 236 pmol/mg). CM-1 has potential application as a unique biochemical marker in joint diseases involving articular cartilage degradation.
Facts and fictions, chronicle, romance and Arthurian narrative in England, 1300-1470

This dissertation examines the relationship between chronicle and romance traditions of Arthurian narrative in England and Scotland in the late Middle Ages. Before Thomas Malory made large portions of the French Vulgate cycle of romances available to an English-speaking audience, Geoffrey of Monmouth's ' Historia Regum Britannie', mediated through various translations and adaptations, was the major source of information regarding the Arthurian past. This narrative, which was generally considered to be an historically accurate record of events, interacted with romance traditions in a number of ways. It is therefore possible to examine late medieval attitudes towards the historicity of Arthur, and the relationship between facts and fictions in historical writing. A variety of chronicle and historical narratives are examined, such as Robert Manning's 'Chronicle'. John Trevisa's translation of the 'Polychronicon', and Andrew Wyntoun's 'Original Chronicle of Scotland'. Complete chapters are devoted to Sir Thomas Gray's 'Scalacronica' (c. 1355), the alliterative ' Morte Arthure', and John Hardyng's 'Chronicle' (c. 1450-1463). By examining texts which seek to present a factual account of Arthur's reign, it becomes clear that a sharp distinction was drawn between the narrative found in the Galfridian tradition, and that which emerged from French romances. Chroniclers were careful to distance romance material from their historical narratives, but some attempted to employ romances in order to enrich the thematic concerns of their works. Transcriptions of the Arthurian portions of Thomas Gray's 'Scalacronica' and the first version of John Hardyng's 'Chronicle' are included. Two romance texts are also explored, 'Sir Gawain and the Green Knight' and 'The Awntyrs off Arthure'. These accounts of ficticious adventures do not claim to be accurate accounts of real events, but by using the chronicle account as the setting for romance narratives the poets utilized the themes of Arthurian history, and implied that their respective adventures have implications for the understanding of the British past. We see throughout these texts an early attempt to apply methods of critical scholarship to the distant past, and to distinguish between the fables which had accumulated around Arthur's court and what passed for the truth concerning Britain's greatest king.
Voice from the borderland, Rebecca Harding Davis and the Southern roots of American social protest fiction

Rebecca Harding Davis's radical voice of social protest emerges out of her roots in the liminal culture of antebellum western Virginia. In her hometown of Wheeling, Davis grew up positioned where East met West, where North met South, and where the slaveholders' mythology of pastoral paternalism met the rising forces of industrial capitalism. Reared north of the Mason-Dixon line but in a slaveholding society, Davis always cherished her Virginian background and preserved a fond nostalgia for the Southern way of life. An important part of Davis's borderland cultural heritage was the rhetoric used to defend slavery, in both fiction and nonfiction. The tradition of the plantation novel and depictions of white "wage slaves" in responses to Uncle Tom's Cabin suggest a link between Southern literary tradition and Davis's innovative social realism. Davis's dualistic cultural vantage point led her to challenge readers' easy assumptions about slavery, industrialism, and American myth-making. Her disposition for provoking her audience into multiple-angle vision shows up especially strongly in her early, extremely socially-conscious work. "Life in the Iron Mills" and 'Margret Howth' both invoke the rhetoric of wage slavery to present industrial poverty as an overlooked social injustice threatening the very roots of American identity. Davis's other early stories in the 'Atlantic Monthly' also manipulate stereotypical Northern and Southern views of slavery to demonstrate the weak spots in both. As mystery fiction from the 1860s and later children's stories demonstrate, the slavery controversy was, for Davis, never a clearcut issue. In ' Waiting for the Verdict', she enacts her life-long tendency to see things from both sides of the North-South border. As a result, Davis's post-bellum miscegenation plot proves to be as much about recuperating ex-slaveholders as ex-slaves. Davis's first-hand understanding of and strong attraction to Southern culture makes her a more complex author than has been previously recognized as well as a significant bridge figure between the literature of the Old South and mainstream tradition.
Frequency-domain equivalents for passive networks

This thesis presents efficient methods for constructing an equivalent of an immittance matrix of a passive electric network based on either infinite-dimensional theory or fitting of measured (calculated) frequency responses. The immittance matrix can be used: (1) To represent a frequency-dependent equivalent of a large electric network, e.g. an interconnected power system, with respect to prespecified terminal(s), in a wide frequency range for (a) analyses of electromagnetic transients, and (b) analyses and synthesis of controllers, or (2) To represent a frequency dependent equivalent of electric apparatus, e.g. a power transformer, in a wide frequency range, to investigate its terminal behaviour with respect to an external phenomenon (black-box representation). Requirements for the equivalent immittance matrix to provide stable results are that (1) all its poles must lie in the left-half plane and, (2) it must represent a passive network. Immittance matrix of a passive network represents a positive real system. Necessary and sufficient conditions for an immittance matrix to represent a passive network, for both rational transfer matrices and state-space matrices, are presented. Based on developed transforms of these conditions, direct methods, for testing positive realness are deduced. The methods and the corresponding algorithms require only evaluation of a set of simple algebraic conditions. These provide alternative procedures to the application of positive real lemma. Based on these algorithms, positive realness of an equivalent is guaranteed. Based on the following two approaches, a finite-dimensional, linear, and passive model of a network, represented by an immittance matrix, is deduced. (1) The first approach is based on solution of a special class of linear hyperbolic partial differential equations using infinite-dimensional theory. Passivity and stability conditions are ensured. (2) The second approach is based on approximation (fitting) of measured (calculated) frequency responses using either a rational immittance matrix or a state-space representation. Stability and passivity conditions for the model are imposed during optimization fitting process. Applications of the developed approaches and corresponding algorithms are demonstrated based on obtaining frequency-dependent equivalents of (1) a large 500kV transmission system, and (2) a three-phase distribution class transformer.
Food production in urban areas, a case study of urban agriculture in Accra, Ghana

Urban Agriculture is an important feature in several sub-Saharan African countries. Most urban farmers are from a rural background which prompts them to choose urban farming over other informal sector activities. Many Ghanaians move to urban Ghana in search of employment in the formal sector. However, as explained by the labour-surplus theory, many urban residents are not able to acquire employment in the formal sector. Thus, those who are not able to acquire salaried income are compelled to seek income from the informal sector. One of the informal sector activities that attracts many of the formally unemployed is urban agriculture. Apart from the fact that many urban residents are formally unemployed and consequently seek income from the informal sector, many formally employed urban residents do not earn enough to sustain themselves and their families. This is explained by the dependency theory of the Third World. Those who do not earn enough, thus the underpaid, are compelled to seek extra income from the informal sector. That many urban residents choose urban agriculture instead of other informal sector activities or in addition to other informal activities is explained by the cultural lag theory. They have a rural background, they have previous knowledge, thus skill, in farming. There are two main types of urban agriculture: enclosed farming and open-space farming. On the one hand, enclosed cultivators are mainly middle/upper class who cultivate for home consumption. On the other hand, open-space cultivators are lower class who cultivate for sale. While most of the open-space cultivators in Accra are from the northern part of Ghana where infrastructural development lags behind, most enclosed cultivators are from the more developed south. Since most open-space cultivators are poor, they depend on their social network members for an efficient practice of urban agriculture. For example, many of them acquire farmland through the assistance of network members. In addition, they borrow capital from network members to buy agricultural inputs. Urban agriculture is a permanent feature. At the moment, the emphasis is on open-space farming. In the near future, emphasis will be on enclosed farming. Both open-space farming and enclosed farming are small-scale. However, in the distant future, the emphasis will be on commercialized or large-scale farming.
Socio-ethical issues of prenatal testing, a content analysis of patient and trade literature

Women require accurate information about the benefits and harms of prenatal testing in order to determine what is in their best interests, and the best interests of the unborn fetus they are carrying, or hope to carry in cases of assisted reproduction. When the tests are inaccurate, or women are being misinformed about the purposes of various screens and tests, healthy, wanted fetuses could be aborted; and unhealthy fetuses, who might have been aborted with accurate information, are born. Misinformation, or a lack of information, undermines a woman's right to make decisions about her own life. There are also wider moral implications of any decision made with respect to prenatal testing. If she had access to information on how her decision impacts society at large, she may make another decision. This thesis explores whether enough printed information on prenatal testing is provided to individual women offered testing.
Application of hetero Diels-Alder methodology, towards the synthesis of martinelline

This thesis is a summary of research conducted since September 1997 at the University of Toronto in the laboratory of Dr. Robert A. Batey. This manuscript is divided into three chapters: (I) Introduction, (II) Results and Discussion, and (III) Experimental. The first project describes the synthesis of 4-arylhexahydropyrrolo[3,2-' c']quinolines. The one pot reaction of substituted anilines, benzadehydes, and 'N'-protected 2-pyrrolines under catalysis by dysprosium(III) triflate afford the desired 4-arylhexahydropyrrolo[3,2-'c']quinolines in good to excellent yield with poor diastereoselectivity. The reaction proceeds in high yield with a variety of electron donating and electron withdrawing substituents on the benzaldehyde. Reaction with electron poor anilines affords the desired adducts in good yield. The presence of electron donating groups on the aniline results in impure products. The use of water as a co-solvent in the reaction yields very good diastereomeric excesses favoring the ' endo' diastereomer. A new protocol for deprotection of these adducts is discussed. Re-investigation of the known two component coupling reaction to afford the martinelline skeleton is also described. In the second project, the scope of dienophiles for this coupling reaction was broadened by the discovery that 'N'-protected 2-pyrrolidinols performed comparably to the 'N'-protected 2-pyrrolines in the two component coupling reaction. The use of 2-hydroxypyrrolidine-1-carbothioic acids as dienophiles in this hetero Diels-Alder reaction is also reported. A two or three component coupling reaction with these dienophiles affords novel hexahydropyrrolo[3,2-'c']quinolines, and an efficient avenue into the guanidine moieties of the natural product. An improved synthesis of the martinelline side chain, a known natural product itself, is also described.
Active Living/Healthier Lives, the Importance of Active Living in the Lives of Exceptional Children

This narrative inquiry is the first step in a journey. It is rooted in my personal and practical knowledge, my experience as a physical education specialist and an educator of young children and in my experience with the struggles of exceptional children. It is anchored in the belief that ACTIVE LIVING (physical activity, movement and active play) is part of a child's natural and instinctual expression and is integral to their education, health and well-being. It takes into consideration the possible connection between the decline in children's active living levels and the growing numbers of learning-disabled children that fill our classrooms. I refer to children who struggle with inattention, hyperactivity and impulsivity and who are often identified as Attention Deficit Hyperactivity Disorder (ADHD). Current practice recommends stimulant medication. This inquiry promotes the positive implications of active living as a realistic alternative to, or as a component of, a comprehensive treatment programme for these children.
The greedy, the naive, and the optimal multicast routing, from theory to Internet protocols

This work studies the problem of multicast routing both at a theoretical and a practical level. Multicasting involves the distribution of the same data to several receivers at the same time. Efficient multicast routing can reduce the communications cost of the distribution tree. In this document, we extend and study the most widely used routing algorithms in a variety of problems, and we compare their performance theoretically and through simulations. First, we study how the asymmetry of directed networks and the membership behavior affect the performance of these algorithms. We prove bounds for the various cases of these problems in a worst case analysis. Second, we propose algorithms for multicast connections where the users have different quality expectations from the multicast connection. We prove bounds for the performance of our algorithms, and examine their performance in a variety of scenarios through simulations. Third, we propose, QoSMIC, a multicast protocol for the Internet. A major advantage of QoSMIC is that the routing decisions consider the quality requirements of the users. In addition, the protocol limits the role of pre-configuration decisions, which cause problems in the employment of some previous protocols. Another important feature of the protocol is its flexibility; it can scale to large networks, and it can adapt and evolve with the needs of the applications and the requirements of the users.
Identification and partial characterization of a putative allatostatin receptor in the midgut of the cockroach Diploptera punctata

A putative receptor for the peptide Dip-allatostatin 7 (Dip-AST 7) was identified in the midgut of the cockroach, 'Diploptera punctata' and was partially characterized using a radioligand-binding assay. The midgut contains a single binding site for Dip-AST 7 with Kd of 14 ± 2.2 nM and Bmax of 1.5 ± 0.1 pmol/mg membrane protein. Binding was saturable, specific and reversible and is physiologically consistent with a receptor. The relative affinity of other members of the Dip-allatostatin family of peptides was determined using a single-point competitive binding assay. The rank order of competitive potency of the allatostatins tested was: Dip-AST 7 > Dip-AST 2 > Dip-AST 5, 9, 11 > Dip-AST 13. A synthetic pseudopeptide analog of allatostatin, AST(b)[straight phi]2, was not an effective competitor for the putative allatostatin receptor.