VictorJuiz/thesis huggingface dataset:
Proexendin-4 processing in vitro and in vivo

Glucagon-like peptide 1 (GLP-1) regulates blood glucose principally through stimulation of glucose-dependent insulin secretion. The peptide exendin-4 (Ex-4), isolated from the venom of the Gila monster 'H. suspectum', is a potent agonist of the GLP-1 receptor 'in vivo' and ' in vitro'. It is not known however whether proexendin-4 (proEx-4) can be expressed and post-translationally processed in mammalian cells ' in vivo'. Given the amino acid residues that flank mature Ex-4, we hypothesised that Ex-4 could be generated by both furin- and prohormone convertase (PC)-mediated cleavage events. The processing profile of proEx-4 was therefore examined 'in vitro' in heterologous mammalian cell-lines stably expressing the proEx-4 cDNA, as well as 'in vivo' in transgenic mice expressing proEx-4. The cell lines analyzed included the fibroblast baby hamster kidney (BHK) cells containing the ubiquitous convertase Furin, mouse pituitary corticotroph AtT-20 cells which contain high levels of PCL and islet A InR1-G9 cells which contain high levels of PC2. Radioimmunoassay and reverse-phase high pressure liquid chromatography were employed to determine the proEx-4 processing profile for each cell-line and in selected tissues and plasma from transgenic mice. All of the cell lines demonstrated the presence of a peak in the elution position of synthetic Ex-4. Transgenic mice, under the control of an inducible metallothionein promoter, were also shown to express and process proEx-4 to bioactive Ex-4 in both endocrine and nonendocrine tissues and to release Ex-4 into the circulation. Thus, these results demonstrate that lizard proEx-4 can be expressed and processed to Ex-4 in a variety of different mammalian cells.
Adaptations to Short-Term Aerobic Training in Younger versus Older Women, Plasma Volume and Cardiac Function

The purpose of this study is to elucidate responses to short term aerobic training (STAT) among women to determine: (1) hypervolemic and cardiac function responses and; (2) the influence of hormone replacement therapy (HRT). A total of 39 females participated in the STAT program; 15 younger (19-29), 12 postmenopausal women undergoing HRT, and 12 nonmedicating postmenopausal women (60-75 years). Cardiac function was assessed using exercise radionuclide ventriculography. Evans Blue dye dilution was used to determine plasma volume (PV). V¤O2max was directly measured during cycle ergometry. Training consisted of ten sessions of cycling over two weeks at 65 to 75% of HRmax. PV and V¤O2max measures were analyzed using an ANCOVA and measures of cardiovascular function were assessed using three way repeated ANOVA. All groups demonstrated similar magnitude of increase in V¤O2max (13-17%) but without significant change in supine exercise radionuclide measures. PV expansion (7%) was observed among younger females (p < 0.05). HRT conferred no differing hypervolemic or cardiac responses. This study suggests adaptations following STAT among women do not result from central adaptations.
Phenotypic and genetic characterization of borderline oxacillin-resistant Staphylococcus aureus

Phenotypic and genetic characterization was performed on 38 ' mecA' negative BORSA isolates with oxacillin MICs, ranging from 1-8 [mu]g/ml (resistance >=4 [mu]g/ml). The majority of BORSA strains (26/38) shared one major DNA profile (type A) by PFGE. Of these 26 type A isolates, 25 were susceptible to the group V phages (phages 94 and 96), 21 harboured a 17.2 kb plasmid, 25 had high penicillin MICs >=32 [mu]g/ml), and 21 demonstrated multiple bands upon Southern blot hybridization of ' Hind'III-genomic DNA with a 'blaZ' probe. An equal number of bands also hybridized with a probe corresponding to the putative transposase gene of Tn'552'. The other non-type A isolates (12/38) were variable in their characteristics and did not exhibit multiple copies or either 'blaZ' or Tn552. The ß-lactamase region from the 17.2 kb plasmid of a type A isolate (SB1) was successfully cloned into a sensitive strain of 'S. aureus' RN4220 using a shuttle vector. Although the penicillin MIC (256 [mu]g/ml) increased, no increase in oxacillin MIC (0.25 [mu]g/ml) was detected. The transformant had high-lactamase activity comparable to type A BORSA. In type A BORSA, there is evidence suggesting the presence of a ß-lactamase mediated mechanism, but the ß-lactamase region alone from a 17.2 kb plasmid present in type A BORSA is not solely responsible for borderline-resistance. Multiple mechanisms of resistance in addition to ß-lactamase may be involved.
Construction and preliminary characterization of papaya mosaic virus as an expression vector for the presentation of foreign epitopes

Papaya Mosaic Virus (PMV) is a plus-sense RNA plant virus and forms flexuous, filamentous rod-shaped particles. An infectious PMV clone was modified to create a gene expression vector which would display foreign epitopes on the surface of viral particles. An epitope from the hepatitis C virus (HCV) core gene was inserted into the amino terminus (N-terminus) of PMV's capsid protein (CP) gene, thereby creating a fusion protein. The N-terminus region was chosen because it is believed to project outwards from each CP of the assembled virus particle. This construct was found to be un-infectious, likely because steric hindrance from the foreign epitope interfered with virus assembly. To alleviate the steric hindrance obstacle, the PMV clone was modified by duplication of the CP gene, followed by insertion of foreign epitopes into one of the CP genes. Since both species of CPs should be utilized during viral assembly, this would ease steric problems by spacing out the foreign epitopes. Epitopes from the HCV core gene and from the breda virus (BRV) nucleocapsid gene were chosen for insertion into this duplicated CP vector--the latter gene was chosen because the available BRV antibodies will be useful for future detection of the protein. The constructs were infectious in 'Chenopodium amaranticolor', PMV's local lesion host. However, infectivity tests with 'Carica papaya', PMV's systemic host have not been completed. A PMV-based expression vector should be feasible and will have many useful applications.
Effect of dilution in glycemic testing

To assess the effect of dilution on postprandial glycemia and its consequences for glycemic testing and diabetes screening, 25g oral sucrose, glucose, and fructose tolerance tests and 75g oral glucose tolerance tests (75g-OGTT) were administered to nondiabetic subjects at different dilutions in three experiments. In the first study, glycemic responses to the three 25g sugar meals were significantly increased by a 3-fold dilution from 200ml to 600ml (P < 0.05). The same was found in the second study: a 3-fold dilution of a 75g-OGTT from 300ml to 900ml significantly increased glycemia (P < 0.05). Increases however occurred only at intermediate time points, not at the diagnostically relevant 2h-point. In the third study, replicated 75g-OGTTs at identical levels of dilution were found to have no or the opposite effect on glycemia in a larger cross-section of subjects. Furthermore, no meaningful effect was observed on reproducibility of results, expressed as the intra-subject coefficient-of-variation. It was concluded that dilution might raise glycemia with some ambiguity upon repeat testing. This effect may account for some of the variability in glycemic testing, although it will likely not confound diabetes screening using the 75g-OGTT.
Characterization of N-GAIP, a novel RGS protein

RGS proteins (regulators of G protein signaling) suppress G-protein dependent signaling by physical interaction with certain G$\sb\alpha$ subtypes, stimulating GTP hydrolysis or sequestering effector binding sites on the $\alpha$ subunits. We have identified a novel RGS member, N(neural)-GAIP in neuroendocrine cells (pituitary and pancreatic islet) and brain, with 74% identity to GAIP (G-alpha interacting protein) within the conserved RGS domain. In situ hybridization analysis of brain regions identified hippocampus and cortex as primary sites of N-GAIP expression, with the pyramidal cells of the hippocampus and the granule cells of dentate gyrus containing the major N-GAIP expressing neuron cell bodies. RACE analysis was using to establish the 5$\sp\prime$ end of the N-GAIP coding region, identifying an 242 amino acid open reading frame. In vitro, GST/N-GAIP fusion protein binds G$\sb\alpha$ subunits in an AlF$\sb4\sp-$-dependent manner with the relative affinity: $\rm G\sb{o\sb\alpha},\ G\sb{\alpha\sp{i3}} > G\sb{\alpha\sp{i1}} > G\sb{\alpha q} {>>>} G\sb{\alpha\sp{s}}$. Binding of constitutively activated mutant G$\rm\sb {o\sb\alpha}$ and G$\sb{\alpha\sp{i3}}$ to N-GAIP is very weak and is not dependent on AlF$\sb4\sp-.$ Our results suggest that N-GAIP may be a better suppressor for G$\rm\sb{o\sb\alpha}$ signaling than GAIP.
AHSG/Fetuin Regulates Ssteogenesis and Inflammation

AHSG/fetuin is a serum glycoprotein, which accumulates in mineralized bone and has been described as a reverse acute phase reactant. AHSG binds to TGF-ß/BMP cytokines 'in vitro', and suppresses TGF-ß-induced osteogenesis in bone marrow cell cultures. However, AHSG-deficient mice were recently reported to be anatomically normal at birth. In this study, I examined the effects of AHSG-deficiency on bone growth and homeostasis, as well as on the response to inflammatory agents, two compartments where TGF-ß/BMP cytokines are known to be active. AHSG-/- mice displayed abnormal chondrocyte organization in femoral growth plates and had shorter bones due to reduced bone growth in young mice. Furthermore, AHSG-deficient mice displayed increased bone remodeling and adipogenesis in the bone marrow. Three-point bending tests indicated that the material properties of AHSG -/- bones declined more rapidly with age compared to AHSG +/+ resulting in weaker bones. Histomorphometry of femoral bone sections revealed increased bone formation rates and osteoblasts/surface in AHSG -/- mice at 3 months of age, while formation rates were significantly less in AHSG+/- mice relative to AHSG +/+ mice. A model is proposed to accommodate this unusual gene dosage effect of AHSG, where an AHSG concentration gradient in the marrow regulates the availability of TGF-ß/BMP cytokines, and thereby the recruitment of osteoprogenitor cells during the bone remodeling process.
Image-based methods of terrain rendering

Terrains are often seen in many graphics applications which require interactive walkthroughs. While very common, they can be difficult to render at interactive rates, since they may be composed of millions of polygons. This thesis presents an image-based method of rendering terrains that produces detailed impostors which can be drawn at constant frame rates, independent of the number of triangles in the terrain. A spectrum of image-based rendering methods is discussed, and four methods are implemented with increasing success. image quality is examined, and timing results of an interactive fly-by over the final terrain impostor are compared with a fly-by over the original terrain geometry.
Valuing English, an ethnography of a federal language training program for adult immigrants

This institutional ethnography of a Canadian federal language training program for adult immigrants explores the historical and sociological discourses that inform the field of ESL for adult immigrants and the attendant ideologies of language that accompany the notion of immigrant integration through language learning. The study zeroes in on one LINC program (Language Instruction for Newcomers to Canada), housed in a Somali immigrant serving organization in Toronto. Local and extra-local discourses converge in the site, policy becomes practice, and the ideologies and practices of the program and its participants are considered to account for the ways that institutional and social practices shape the social relations of the program. Lastly, the study considers a few examples of classroom linguistic interactions to look at how the notions of linguistic and cultural difference are constructed in and by the program to reproduce elements of Anglo-Canadian linguistic and cultural dominance.
Capillary-muscle fiber morphometry in female diabetic & impaired glucose tolerant rats

Muscle morphology was investigated in diabetic (D; n = 8) and impaired glucose tolerant (IGT; n = 7) female rats. Size changes were assessed by measuring fiber area (FA), and perimeter (P). Capillary supply was quantified using number of capillary contacts (CC); individual capillary:fiber ratio (C:Fi); FA/CC; and P/C:Fi. FA and P were significantly (p $\le$.05) decreased in D and IGT rats compared to the controls. The capillary supply was significantly (p $\le$.05) reduced in the D and IGT groups compared to the controls. The decrease in fiber area in Type I and II fibers was disproportionate to the decrease observed in the capillary supply. FA/CC ($\mu$m$\sp2$) in D (I:757 $\pm$ 35.5; II:405 $\pm$ 15.0) and IGT (I:780 $\pm$ 29; II:538 $\pm$ 28) rats were significantly reduced versus controls (C1 I:1336 $\pm$ 40.5; II:776 $\pm$ 28; C2 I:1033 $\pm$ 28; II:641 $\pm$ 18), indicating a decrease in diffusion distance from the capillary to muscle fiber. In contrast to FA, muscle fiber perimeter was maintained in relation to the capillary supply, such that P/C:Fi ($\mu$m) was not significantly different between the four groups. The data suggest that: (1) decreased diffusion distance may be an adaptive response to optimize the delivery of hormones and (2) the maintenance of perimeter in relation to capillary supply may be related to diabetes-induced changes in insulin responsiveness.
Investigation of turbulent flow in a reciprocating engine using particle image velocimetry

A fully optical water analog engine has been designed and constructed for modeling engine flow. A study of the velocity fields, in the latter part of the intake stroke, near the piston surface shows the flow to be turbulent and three-dimensional in the mean. For the first time in an engine study, terms from both the Reynolds and kinetic energy equations have been extracted and compared. A study of the Reynolds equation shows that a greater percentage of the convection and Reynolds stress transport terms have magnitudes which are larger than the diffusion terms. Results from the mean and turbulent kinetic energy equations show that a greater percentage of the production and Reynolds stress transport terms have magnitudes which are larger than the dissipation and viscous stress transport terms.
New social relations in Argentinean agriculture, capitalist sharecropping in the Pampean region

The ideological and 'political' factors that inform the emergence and development of contemporary share tenancy relations in the Argentinean Pampean region are analyzed in this thesis. Proponents of both Modernization and Marxist theories analyze share tenancy as a backward economic form that is therefore incompatible with economic change and the development of productive forces. Thus, the main theoretical schools devoted to the study of social change are ill equipped to study the relationship between share tenancy and agricultural expansion. Drawing upon an analysis of sharecropping in the Ecuadorian Sierra and in California, an alternative ideal type of capitalist share tenancy is put forward in order to bridge this theoretical gap. State policy plays an outstanding role in this ideal type. Indeed, state policy in Argentina was consistently reformist regarding the land market, exhibiting an open, anti-large landowners slant since the early 20th century. The debates in the Chamber of Deputies that took place in 1929, 1948 and 1964 on the laws regulating land leasing are examined in this context. Analysis of discourse unravels the meanings assigned by the different political parties--'radicales', conservatives and 'justicialistas '--to state intervention. The political and ideological context that emerged paradoxically fostered share tenancy from 1960 onwards as a legitimate social form. Thus, the historical development of share tenancy has been mediated by ideological forces and political clashes that are both irrelevant to the economic logic of the actors involved in share tenancy and external to the social conflicts in the rural setting. Finally, the developments of the 1990's--within a context of expansion of production--increased the importance of land leasing in Pampean agriculture, and implied a greater separation of the landowner from the productive functions related to agriculture. According to statistics, sharecroppers played a prominent role in the growth of Argentinean agriculture. Hence, sharecropping retains a stable place in Argentinean agriculture amidst the development of new forms of organization of production which exhibit higher levels of capitalist development.
Robust false memory effects under conditions of paired-associate learning

Substantial levels of false recall and recognition occur for lists of words semantically related to an unpresented word (Deese, 1959; Roediger & McDermott, 1995). Manipulations that have attenuated this "false memory effect" have reduced the probability of the presented words being linked semantically. We employed a paired-associate learning procedure to de-emphasize the relation between list items and to make individual list items more distinctive. Subjects learned 12 word associates either (a) as 12 individual words (standard condition), (b) as 12 words, each paired with a number (number-noun condition), or (c) as 6 two-word pairs (noun-noun condition). If pairing words with numbers minimizes semantic analysis of each item and reduces the probability of forming links between items, the false memory effect should be reduced. However, the results indicated increased false memory in the number-noun condition, relative to the standard and noun-noun conditions, which did not differ. Correlational analyses were used to explore the causes of the false memory effect.
Reducing the bias in contractor prequalification using Data Envelopment Analysis

Data Envelopment Analysis (DEA) is a linear programming tool that can handle multiple inputs and outputs in a non-parametric fashion. DEA provides an unbiased analysis of Decision Making Units (DMUs). It can provide a more sophisticated alternative to prequalification systems as well as eliminate any subjectivity from the decision-maker. A three-stage model, employing an output-oriented variable returns-to-scale DEA model, is proposed and compared against an established model. The three stages involve receiving a letter of required bonding, followed by the DEA analysis, and ending by reducing the amount of prequalified contractors to a predetermined amount, referred to as shortlisting. The DEA model produced average efficiencies between 70 and 85 percent for the seven contracts evaluated. Many of the top and bottom contractors received similar rankings in each of the two models. DEA should be a welcomed addition to the construction industry.
The influence of wheat bran and phytic acid on early biomarkers of colon carcinogenesis

It is unclear whether the previously observed colon cancer protective effect of wheat bran (WB) is due to its fiber and/or phytic acid (PA) components since pure PA (1-2%) has also been shown to be protective of colon cancer in rats. Thus, the objectives of this study were to determine whether WB, due to its fiber and/or its PA, alters early biomarkers of colon cancer risk (aberrant crypt foci (ACF) and indices of cell proliferation) and whether endogenous and exogenously added PA differ. Possible modes of WB and PA action were also investigated. Five groups of azoxymethane-treated male F344 rats were fed, for 100 days, a basal control diet (BD), BD supplemented with either 25% WB, 25% dephytinized WB (DWB), 25% DWB plus 1.0% PA or 1.0% PA. All treatment diets reduced (p < 0.05) the number of sialomucin (SIM) ACF (by 43-66%), the degree of ACF luminal alterations (by 7-14%) and indices of cell proliferation (maximum 26-57%) versus the BD. Exogenous PA also reduced the number (by 31%) and size of ACF (by 39%) versus the BD. Some indices of cell proliferation were significantly increased (by 11-42%) upon dephytinization of WB. The treatment diets also increased the rate of apoptosis (by 135-217%) and cell differentiation (using lectin staining; by 144-168%) in various regions of the crypt. There were no major changes in indices of colon mucosal and liver lipid peroxidation, colonic butyrate production or serum and femur calcium or iron levels. However, versus the BD, all treatment diets reduced colonic pH, the WB-containing diets reduced &square;-glucuronidase activity, the WB diet increased total colon SCFA production and the PA diet decreased serum zinc. It was also observed that SIM ACF are more advanced types of ACF. It is concluded that WB significantly reduced putative early biomarkers of colon cancer risk due, in part, to its PA and dietary fiber. Furthermore, endogenous and exogenous PA are both effective, but exogenous PA is more effective in a low fiber diet. These effects are related to decreased cell proliferation, colon pH and increased apoptosis and degree of cell differentiation. They do not appear to be due to an anti-oxidative mechanism or inhibition of mineral availability.
The effects of HGF, TGF-ß1, IGF-I and IGF-II on neonatal porcine islet-like cell clusters

In this study, the neonatal islet-like cell clusters (ICCs) were cultured in the presence of HGF, TGF-ß1, IGF-I, IGF-II or a mixture of the growth factors. The clusters were analyzed with regards to RNA content, insulin content, insulin secretion and insulin staining. The treatment that caused the clusters to store and secrete the most insulin was selected for in vivo studies. The results indicated that IGF-II treated ICCs were most suitable for the in vivo study. The IGF-II treatment significantly increased the RNA content, insulin content and the number of insulin positive cells/ICC in vitro. Nonetheless, neither 3000 control nor 3000 IGF-II treated ICCs were capable of reversing hyperglycemia in the streptozotocin diabetic mouse model 45 days posttransplantation. This study shows the potential to manipulate the growth and development of neonatal ICC tissue in vitro.
Intercollegiate swimmers' experiences of anxiety and their perceptions of a mental skills training program

This investigation examined intercollegiate swimmers' experiences of anxiety and their perceptions of a mental skills training program. The participants consisted of five intercollegiate swimmers in Canada (m = 3, f = 2). Within this investigation there were two interview phases, a pre- and post-intervention interview. Following the pre-interview and prior to the post-interview the swimmers received six individual mental skills sessions. Eight higher categories emerged including experiences of anxiety, sources of anxiety, performance satisfaction, coaching styles, previous exposure to sport psychology, application of mental skills, perceived benefits and suggestions for the design and implementation of a mental skills training program. This research has implications for coaches and sport psychology consultants interested in learning about athletes' experiences with a mental skills training program and their preferred consulting format. Also, researchers and consultants can gain valuable information about athletes' experiences of anxiety in order to assist in the development of methods to control and reduce heightened anxiety levels.