VictorJuiz/thesis huggingface dataset:
The characterization and initial identification of the elevated carbon dioxide-insensitive Arabidopsis thaliana mutant cnr3-1

Predicting and managing the impact of the projected doubling of atmospheric CO2 during this century necessitates the investigation of the mechanisms governing plant response to elevated CO2. The objective of this study was to investigate the nature and underlying cause(s) of the pleiotropic phenotypes associated with the previously isolated CO 2-insensitive Arabidopsis thaliana mutant cnr3-1. A variety of developmental abnormalities were investigated, including leaf morphology, phase change, flowering time, response to hormones and pre- and post-pollination reproductive development. Previously reported as a single-insert T-DNA mutant, cnr3-1 was discovered to contain two T-DNA inserts. Single-insert lines were subsequently generated and one insert was identified as a lesion in the gene At3g55980. The elimination of the At3g55980 protein confers dominant sugar-insensitive, elevated CO 2-insensitve and shortened silique phenotypes and contributes to dominant early-flowering and large seed phenotypes. Bioinformatic analysis provides some insight into both the regulation of the At3g55980 promoter and potential protein function.
The effect of Korean red ginseng (Panax ginseng C.A. Mayer) on vascular function and influence of derived ginsenosides and polysaccharides

Korean red ginseng's (KRG) effect on vascular parameters and accountability of active components remains poorly characterized clinically. The objective was therefore, to establish a dose-response relationship and contribution of ginsenoside and polysaccharide components by systematically evaluating vascular efficacy of KRG in a series of 3 crossover, placebo-controlled RCT. Study-1 tested escalating doses of KRG on systolic and diastolic blood pressure and showed an insignificant dose-response effect in individuals with hypertension. Study-2 evaluated the relationship of KRG and its isolated ginsenoside and polysaccharide fractions on pulse-wave reflections in healthy individuals, and demonstrated significant improvement in augmentation index with KRG, verifing that its efficacy lies within the ginsenoside fraction. These effects were subsequently translated in study-3 into significant improvement in endothelium-dependant vasodilation with KRG and ginsenosides in healthy individuals. The studies provide a mechanistic basis to clarify vascular effects of KRG and put forward a foundation for component-based standardization of KRG.
Cognitive set shifting using functional magnetic resonance imaging (fMRI) and virtual reality (VR): acomparison between a traditional and a novel ecologically-valid executive function task

This study sought to develop a task that would be both ecologically valid and a "pure" measure of set shifting ability (Office Courier Task; OCT) using virtual reality (VR) technology. A VR Wisconsin Card Sorting Test (WCST) was also developed to allow for a direct comparison to a traditional set shifting task. Twenty healthy participants (9 males) performed significantly better on the OCT than on the WCST (p
Developmental plasticity in the mouse calyx of Held-MNTB synapse

We next showed a genuine voltage- and developmental-dependence in AMPAR kinetic properties and in their underlying quantal events. AMPARs at all ages were effectively blocked by polyamines suggesting a lack of GluR2 in synaptic AMPARs. Our proposal that AMPAR kinetics may be determined by a developmental alteration in the relative abundance of slow gating GluR1 to fast gating GluR3/4 was supported by immunohistochemical analysis and biophysical assays in outside-out patches. Fast AMPAR kinetics was shown to be essential for transmission at high rates without compromising spike amplitude. Thus changes in EPSC kinetics are required for maintaining reliability of synaptic transmission. Little is known about the precise mechanisms that allow high fidelity transmission at specialized synapses in the auditory brainstem pathway where timing information is preserved during sound localization. Being axosomatic, the calyx of Held-medial nucleus of the trapezoid body (MNTB) synapse is an ideal model for studying developmental changes that contribute to this neurotransmission as reliable voltage-clamp recordings of excitatory postsynaptic currents (EPSCs) can be made. We found that NMDARs are rapidly reduced following the onset of sensory inputs. Using pharmacological agents, we showed coincident activation of group I metabotropic glutamate receptors (mGluRs) and NMDARs was required to facilitate NMDAR reduction and that removal of surface NMDARs occurred via clathrin-dependent endocytosis. Pairing presynaptic tetanus bursts with postsynaptic depolarization also induced NMDAR reduction, implicating physiological relevance. This reduction ultimately improved the fidelity of spike firing during high-frequency synaptic activity. Synaptic activity may be therefore be the driving force for gradually phasing out NMDARs from postsynaptic neurons during development. We found a significant age-dependence in the size of EPSCs and whole-cell currents. Shorter decay time constants of NMDA and AMPA receptors (NMDAR, AMPAR) during maturation suggested possible changes in subunit composition. As subunit switching alone could not explain the faster NMDAR kinetics, we suggest morphological changes in the presynaptic calyx may affect glutamate binding. Additionally, developmental differences in synaptic fidelity, depression and recovery from this depression implicated their importance in maintaining high frequency transmission. These results provide important steps towards a comprehensive understanding of both fundamental and specific processes that are critical for the development of synaptic transmission in the calyx of Held-MNTB synapse.
Correlation radiometer measurements of carbon monoxide in Southern Africa during the 2000 dry season

MOPITT-A (Measurements Of Pollution In The Troposphere-Airborne) is a new correlation radiometer that operates from the superpod of an ER-2 aircraft. The instrument is equipped with four channels, three of which are sensitive to tropospheric carbon monoxide. The fourth channel is sensitive to methane. In 2000, the instrument participated in the SAFARI 2000 field campaign in southern Africa, whose goal was to quantify atmospheric and land changes associated with biomass burning processes. Case study retrievals were performed for the September 7th flight, using radiances from a single CO channel. The method employed is a regression scheme that relies on the fact that radiances are mainly a function of the surface temperature and the CO column. The product of the retrieval is a tropospheric CO column based on a constant vertical profile. The instrument is able to distinguish between clean air and polluted air belonging to the so called 'river of smoke', laden with biomass burning material. The results compare favorably with two CO products independently derived from spectra recorded by the Scanning High Resolution Interferometer Sounder (S-HIS) on the ER-2. The precision of the retrievals is of the order of 5 ppbv.
Almonds, glycemic excursions, oxidative stress and risk factors for coronary heart disease

Postprandial hyperglycemia is associated with an increased risk of diabetes and heart disease. Almonds may reduce postprandial glycemia since they contain protein, fat and antioxidants. In healthy subjects, almonds, consumed with white bread, at doses of 30g, 60g, and 90g, reduced glycemic excursions in a dose-dependant manner (r=-0.46, n=38, P=0.004). Furthermore, the 60g almond and bread meal reduced protein oxidative damage as loss of protein thiols (P=0.021), compared to other meals including the bread meal, and the potato and rice meals with added protein and fat. Postprandial glucose and insulin response areas were inversely correlated to the change in protein thiols for the four meals (n=15, P=0.001; and n=15, P=0.008 respectively), providing evidence that the magnitude of the glycemic excursion is a determinant of oxidative damage. Reduced postprandial glycemia, plus endogenous antioxidants, may be part of the reason why almond consumption is associated with reduced CHD risk.
The effectiveness of Bayesian Belief Networks and real-time monitoring technology in facilitating the implementation of water quality regulations

Real-time monitoring technologies may play a valuable role in helping small and rural communities meet existing and emerging water quality regulations. However, errors associated with the technology such as false positive readings must be managed. Bayesian Belief Networks (BBNs) have the ability to integrate sensor information and other operational and physical system data in order to generate probabilities for the reliability of sensors and the state of water quality in a given water distribution system. A BBN was developed for a case study potable water transmission system in Saskatchewan. Sensitivity analysis identified nodes of interest and redundant sampling points and demonstrated the need for special care in the generation of specific conditional probabilities. When the performance of the BBN was evaluated, there was real-time response to changes from typical operating conditions and a correct interpretation of the causes of adverse sensor readings when all available data was entered.
Wall shear stress and intimal thickening in the right coronary artery

Low wall shear stress has been implicated in atherogenesis throughout the arterial tree including the right coronary artery. The objectives of this study were to explicitly test the hypothesis that a correlation exists between atherogenesis and wall shear stress in the right coronary artery, and to determine if it is important to include the effect of branch outflows when assessing this correlation. Post-mortem histological measurements of intimal thickness were compared to wall shear stresses calculated from computational flow modeling in four human right coronary arteries. We found no consistent correlation between intimal thickness and wall shear stress, and also found that ignoring branch flow effects can lead to the observation of a spurious correlation. These findings suggest that wall shear stress does not play a dominant role in the localization of atherogenesis in the human right coronary artery.
Objet de mepris, sujet de langage: L'injure performative et la construction du sujet feminin chez Annie Ernaux, Suzanne Jacob, Violette Leduc et France Theoret

Cette these, qui comporte cinq chapitres, a pour objectif de demontrer que, dans certaines oeuvres d'Annie Ernaux, de Suzanne Jacob, de Violette Leduc et de France Theoret, l'enonce injurieux est un mode d'emancipation pour les narratrices et les personnages feminins. L'injure peut effectivement etre une strategie discursive liberatrice qui permet a une femme injuriee de devenir sujet en critiquant les obstacles empechant son acces a la subjectivite. La demonstration se fera en deux temps: il s'agira d'elaborer une theorisation de l'injure performative au feminin pour ensuite en analyser le fonctionnement dans des textes litteraires qui reveleront differentes strategies forgees par des femmes repliquant a leurs injurieurs. La femme injuriee qui injurie a son tour (un mouvement appele la chaine paradigmatique injurieuse) parvient a avoir prise sur le monde exterieur hostile en s'appropriant un langage qui devait la condamner au silence. Le premier chapitre s'ouvre sur un survol des principaux theoriciens de la performativite (Austin, Recanati, de Souza Filho, Butler, Threadgold) pour ensuite proposer une etude de l'insulte qui en exposera la nature performative, le potentiel subversif. Le second chapitre entamera le volet critique de cette these par le biais d'une analyse de L'asphyxie et de La batarde, deux autobiographies de Violette Leduc, ou il sera demontre qu'en reponse aux insultes de sa mere, Leduc elabore une strategie auto-injurieuse qui rend possible sa venue a l'ecriture. Les armoires vides et L'evenement, deux textes autobiographiques d'Annie Ernaux auxquels est consacre le troisieme chapitre, illustrent quant a eux la dechirure culturelle de l'auteure qui, grace a son avortement clandestin, repond aux insultes dont elle a ete victime en injuriant a son tour et en temoignant de son passe. Pour la poete France Theoret, dont les recueils Bloody Mary et Necessairement putain sont etudies dans le quatrieme chapitre, le deplacement de l'injure sexuelle patriarcale a l'injure fecale donne jour a une voix feminine subversive. Enfin, pour les heroines de Flore Cocon et de Laura Laur, deux romans de Suzanne Jacob dont il est question dans le cinquieme chapitre, les insultes dont elles font l'objet attaquent leur marginalite qu'elles vont reclamer avec leurs repliques.
Beta-cell stimulus-secretion coupling: a role for uncoupling protein 2

A key event in insulin secretion from the pancreatic P-cell is glucose-stimulated mitochondrial production of adenosine triphosphate (ATP). Uncoupling protein-2 (UCP2) is localized to the inner mitochondrial membrane and plays a role as a "typical" uncoupler that modulates the efficiency of ATP production by catalyzing the translocation of protons across the mitochondrial membrane. This uncoupling reduces the protonmotive force that drives ATP synthase activity and thus reduces the ability of the beta-cell to increase ATP levels in response to glucose. The work presented here focuses on the role of UCP2 in the pancreatic beta-cell and the involvement of UCP2 in free fatty acid (FFA) induced beta-cell defects leading to type 2 diabetes. UCP2 was found to negatively regulate glucose-stimulated insulin secretion (GSIS). UCP2 expression is increased by FFAs suggesting a possible causal link between UCP2 and beta-cell defects associated with elevated FFA. Mice fed a high fat diet (HFD) have elevated UCP2 protein levels and blunted GSIS with no compensatory increase in beta-cell mass. Mice lacking UCP2 are resistant to the effects of a HFD on beta-cell function. HFD fed UCP2 ( -/- ) mice show no loss in GSIS and have an increase beta-cell mass. In order to assess the mechanism of enhanced beta-cell insulin secretion in mice lacking UCP2 an in vitro model was developed where isolated islets were exposed to 0.4 mM palmitate for 48 hours. The most proximal consequence of palmitate induced UCP2 levels appears to decrease glucose-stimulated changes in the mitochondrial membrane potential and this diminishes the downstream glucose-stimulated increase in both the ATP/ADP ratio and cytosolic Ca 2+. This leads to an attenuation of GSIS. UCP2 ( -/- ) mice have no loss in beta-cell glucose-stimulated hyperpolarization of the mitochondrial membrane potential and maintain their ability to secrete insulin in a glucose-dependent fashion. Therefore HFD fed mice or palmitate exposed islets lose their glucose sensitivity by a mechanism that likely involves increased UCP2. In addition, UCP2 may also modulate the oscillatory pattern of ATP production and thus oscillations in KATP channel activity, plasma membrane potential and insulin secretion. UCP2 is an important regulator of glucose sensing in the pancreatic beta-cell and upregulation of UCP2 in the pre-diabetic state could contribute to the loss of glucose responsiveness observed in obesity-related type 2 diabetes.
Systematic identification of regulators of cell cycle commitment and a dynamic transcriptional network that communicates growth potential to ribosome synthesis and critical cell size in budding yeast

Size homeostasis requires that proliferating cells co-ordinate their growth and division. In Saccharomyces cerevisiae, this co-ordination occurs in late G1 phase at the point of commitment to cell division termed Start; traversal through Start requires that cells have grown to a critical cell size. The cell size threshold is flexible and is set higher in rich nutrient conditions and in proportion to ploidy. Despite its importance, Start remains poorly understood, in large part because the cell size phenotype has been refractory to conventional genetics. The recent construction of sim;6000 yeast strains deleted for every predicted open reading frame allowed me to systematically identify genes whose deletion confers abnormally small or large cell size. These screens identified 40 potential Start regulators, including Whi5, the long postulated but previously unidentified target of Cln3-Cdc28 kinase at Start. The smallest deletion strains carried disruptions in SFP1 or SCH9. SFP1 encodes a zinc-finger transcription factor while SCH9 encodes a protein kinase, but neither gene product had been well characterised. Numerous experiments demonstrated that although Sfp1 and Sch9 are important for cell growth, they are also bona fide Start repressors. Remarkably, both Sfp1 and Sch9 activated the RP and Ribi regulons, two expansive transcriptional programmes whose expression is rate-limiting for ribosome production. This finding meshed nicely with the cell size screens, as my shortlist of potential Start repressors included 15 ribosome biogenesis factors. I elaborated a control network including Sfp1, Sch9, and the transcription factors Rgm1, Fhl1, and Ifh1 at RP promoters. Sfp1 and Sch9 are controlled by nutrient status at the level of nuclear localisation and abundance, respectively, and appear to tailor a cell's ribosome production to its growth potential. Overall, my data argues that the rate of ribosome biogenesis, dictated by nutrients via Sfp1 and Sch9, modulates the critical cell size threshold at Start by a mechanism that is independent of the known upstream regulators Cln3, Bck2, and Whi5. My work has allowed for a more complete molecular characterisation of Start, elucidated a dynamic transcriptional control network for the RP and Ribi regulons, and illuminated connections between ribosome biogenesis and Start.
On the functions of mammalian SEPT2 during cytokinesis

Septins belong to a growing family of proteins that play important roles in different biological processes such as cytokinesis, neurite outgrowth, neuronal guidance and secretion in a wide range of different organisms including budding yeast and humans. Septins have been reported to be able to form homo and heterotypic filaments in vitro, but the relevance of septin filaments in the above-mentioned biological phenomena remains elusive. Furthermore, even though septins have been implicated in many processes that require precise regulation of the actin cytoskeleton, the link between septins and the actin cytoskeleton is still unclear. Therefore, this thesis aimed to examine the role of septins during cytokinesis and the link between septins and the actin cytoskeleton by a number of different experimental methods. First, I examined the importance of different regions of a mammalian septin, SEPT2, in polymerization; the GTPase and the putative coiled-coil domains were analyzed. Consistent with the reported findings, the GTPase domain of the SEPT2 was important in septin polymerization. However, in contrast to the previous findings, the putative coiled-coil domain of the SEPT2 was also important in the filamentous staining pattern of SEPT2 in cultured cells. Second, to understand the link between septins and the actin cytoskeleton, I performed binding assays and found that septins are linked to the actin cytoskeleton by associating with non-muscle myosin II (myosin II). Interestingly, association of septins and myosin II was necessary to regulate the activity of the myosin II as dissociation of the septins and myosin II decreased the level of di-phosphorylated myosin light chain, and subsequent disruption of contractile filaments and cytokinesis. Finally, in contrast to previously reported data, septins co-localized with the plasma membrane when the stability of the actin fibers were altered. In addition, the C-terminus of various Ras proteins co-localized with septins suggesting that under certain conditions septins demarcate lipid microdomains. From these findings, as well as other reported data, models are proposed to explain the roles of septins during cell division.
The Royal Ontario Museum collection of Gandhara sculpture

This thesis focuses on a forty-three piece collection of Gandhara sculpture in the Royal Ontario Museum in Toronto, Canada. Although individual pieces of the ROM's Gandhara sculpture are widely known to scholars, much of the collection has never been published. This is the first time the ROM sculptures have been described and analyzed as a collection. The thesis is organized into two parts. Part one includes chapters on Gandhara's ancient history, physical geography, and the history of the Buddha image in ancient India. Particular emphasis is placed on the era of the Kushan empire from the 1st to 4th century AD when the school of Gandhara sculpture achieved its highest levels of production and craftsmanship. Part two is a complete catalogue of the collection of forty-three sculptures, with photographic plates, physical descriptions of each object, museum accession numbers, and detailed commentary on the features and significance of each image.
Variation in reduction strategies of dutch word-initial consonant clusters

The main goal of this thesis is to investigate between-individual and within-individual variation in consonant cluster reduction strategies (C 1C2 is realized as C1 or C2) among young children. The empirical base of the study is a Dutch database with over 9,000 instances of C1 and C2 realizations of 23 word-initial consonant clusters from 45 children aged between two and three years old. A major contribution of the thesis concerns the methodology of the study, in which both between- and within-child variation as well as between- and within-cluster variation are tested in a systematic way. One of the findings is that within-child variation is very limited, whereas between-child variation occurs. Thus, although an individual child is consistent in his/her reduction strategy, there is a difference between children in the way clusters are typically reduced. Some clusters are always reduced in one particular way (e.g. /sp/, /sk/, /pl/, /pr/, /bl/, /br/, /tr/, /dr/, /kl/, /kr/, /fr/, /xr/, /tw/, /sw/). In other clusters, either target segment can be realized (e.g. /st/, /sx/, /sm/, /sn/, /sl/, /kn/, /fl/, /xl/). It was furthermore found that there are implicational relationships between some clusters, i.e., realizing C2 in cluster x implies realizing C2 in cluster y, but not vice versa. Neither the difference between stable and variable clusters, nor the implicational relationships between some clusters, can be explained by the feature [sonorant] alone. Instead, the variation in reduction strategies is the result of a difference in prosodification, which is caused by the fact that some children tend to avoid onsets with similar structure in terms of sonority distance and place of articulation. The perception of clusters was tested in a pilot study. The results suggest that it is not always correct to assume that a child has clusters underlyingly. In future research, a stronger focus must be put on the status of the child's prosodic and segmental representation. This can be done only if studies target both production and perception.