VictorJuiz/thesis huggingface dataset:
Frequency, plasticity and information processing

Memory subsystems have different temporal properties, but the common element is activity-dependent modifiability of synaptic transmission properties. This modifiability is a manifestation of plasticity, and occurs following various combinations of stimulus frequency, intensity and duration; numerous mechanisms determine the strength and decay rate of the resultant alterations in transmission efficacy. How a neuron responds to a stimulus depends on which processes have acted recently and on how quickly they dissipate--rapid-onset short-term effects may occur within a spike train. A neuron's frequency-response properties are thus important for plasticity induction and are also modified by it. Long-term potentiation (LTP) and depression (LTD) are produced by high and low stimulation frequencies, respectively; one proposal (the BCM hypothesis) is that the direction of plastic change (LTP vs LTD) depends on the amount of activation relative to some threshold, which varies according to stimulation history. Because there are direct connections to all hippocampal subfields from entorhinal cortex, this suggests that their relative strengths could be modulated to "channel" signals via different pathways. Further, if transmission properties are modified "on-line" by rapid induction of plasticity, this implies that spike trains dynamically "self-select" how they are processed based on their spatiotemporal parameters. I have examined the effects of stimulation at various frequency ranges on signal transmission in the dentate gyrus of the hippocampus, and have found that the very low frequencies (.03-.10 Hz) typically used as "monitoring" stimuli can significantly bias responses. I show that these responses are normally very unstable, which further complicates the interpretation of results. I have also confirmed the history-dependence of plasticity--the "crossover" point at which LTD gives way to LTP depends on whether a series of frequencies is presented in ascending or descending order. My data do not confirm the BCM hypothesis specifically--they also permit the interpretation (the "neutral zone" hypothesis) that there is a wide moderate-frequency "labile range" within which no plastic changes occur. A final experiment to test these two alternatives provided greater, but not conclusive, support for the BCM hypothesis.
Molecular gas in interacting galaxies

A systematic study of the molecular gas properties in strongly interacting galaxies (SIGs) has been undertaken, which includes two parts: (1) a statistical study of a large, optically-selected, complete sample of SIGs; (2) a case study of the nearest colliding pair NGC 4038/9 ("the Antennae") with multi-transition data of both 12CO and 13CO. Consisting of 126 galaxies in 92 systems, our complete sample of SIGs includes all the SIGs in the northern sky with optical magnitude ' BT' < 14.5. CO data have been collected for 95 SIGs (59 of which were observed by us) as well as for comparison samples of 59 weakly interacting and 69 isolated spiral galaxies. The statistical analysis of the samples shows that the SIGs, especially the colliding and merging systems, have a higher CO luminosity than isolated spiral galaxies. However, there is no significant difference in the atomic gas contents between the samples. This indicates that the excess CO emission is not due to the conversion of atomic gas to molecular gas, but may be more plausibly accounted for by a lower CO-to-H2 conversion factor 'X'. For the Antennae galaxies, we have obtained high quality, fully sampled, single dish maps at 12CO J = 1-0 and 32 transitions with an angular resolution of 15€ (1.5 kpc), together with 12CO J = 2-1, 13CO J = 2-1 and 3-2 data at selected regions with similar resolutions. Our Nobeyama 45m map recovers twice as much 12CO J = 1-0 flux as was reported by Wilson et al. (2000). The 12CO J = 1-0, 2-1 and 3-2 emission all peak in an off-nucleus region adjacent to where the two disks overlap. The 12CO/13 CO J = 2-1 and 3-2 integrated intensity ratios are remarkably high in the overlap region. Detailed LVG modeling indicates that the 12 CO and 13CO emission come from different spatial components. The 12CO emission originates from a nonvirialized low density gas component with a large velocity gradient. Such a large velocity gradient can produce "over luminous" CO emission, and the derived 'X' factor is an order of magnitude lower than the conventional value. We suggest that the apparently strong CO emission in the overlap region of the Antennae galaxies is due to increased radiative efficiency, possibly because of the large velocity dispersion. A comparison of the CO J = 3-2 emission with the SCUBA 850 [mu]m continuum in the Antennae galaxies shows that CO line emission on average contributes 46% of the 850 [mu]m continuum flux and the ratio of 12CO J = 3-2 to SCUBA 850 [mu]m flux varies by a factor of two across the system. After correcting for the 12CO J = 3-2 contamination, the dust emission at 850 [mu]m detected by SCUBA is consistent with the thermal emission from a single warm dust component with a mass of 1.7 * 107 <math> <f> <rm>M<inf>&odot;</inf></rm></f> </math>.
Transcriptional regulation of E-cadherin in Drosophila melanogaster

'D'E-cadherin/'shotgun', is the ' Drosophila' homologue of vertebrate E-cadherin. 'D'E-cadherin is a calcium dependent, homophilic adhesion molecule that accumulates in adherens junctions of epithelia. The transcriptional regulation of 'shotgun ' was investigated to identify 'cis'-acting regulatory elements. Sequence analysis of the 'shotgun' genes of ' D. melanogaster' and 'D. virilis' identified twelve conserved regions of high sequence identity including a tandem E box, which is a DNA motif found in the promoter of mouse E-cadherin. A genomic construct containing the conserved regions was able to partially rescue the ' shotgun' mutant phenotype. A reporter construct containing the conserved 5' regions except for the tandem E box revealed a near wildtype expression pattern suggesting that this element is not required. The overexpression of 'snail', an E box binding protein, upregulated ' shotgun' expression. In addition, the misexpression of a truncated form of 'D'Ã-catenin resulted in wing blistering.
Operational analysis of high-occupancy vehicle lanes using microsimulation

High-occupancy vehicle (HOV) lanes have evolved as an important transportation supply management strategy for reducing peak-period traffic congestion in many urban areas. In HOV lane planning initiatives, accurate estimation of the travel time differentials between HOV Lanes and the adjacent general-purpose (GP) lanes is crucial in projecting the potential mode shift from solo driving to high-occupancy vehicles. Microsimulation-based operational analysis of traffic provides a promising approach to compute these travel time differentials more efficiently. In addition, microsimulation-based analysis provides the opportunity to evaluate the impacts of HOV lane implementation at a more disaggregate, section-by-section, basis in a corridor. In this research project, an HOV lane treatment plan for Highway 401 in Toronto was developed using the above approach based on a comparative operational analysis of three improvement scenarios. The research results showed the usefulness of microsimulation for evaluating HOV lane improvement options for large freeways on a section-by-section basis.
Girls reading culture, autobiography as inquiry into teaching the body, the romance, and the economy of love

Educating girls is one of the most significant yet problematic developments of the last 150 years. A girl, in the process of her schooling, learns to layer the messages of a logo/androcentric culture over the insights born of her lived experience, muffling and silencing the still, small voice within. I maintain that the educated woman who teaches comes to her profession many times divided against herself. She is expected to teach the very values her life may have taught her to question. Using autobiographical narrative as my methodology, I weave a tapestry from the threads of memory, educational theory, newspaper articles, and popular culture to examine questions of gender and female socialization. I begin by investigating adolescent female psychological development and proceed to consider the relationship of literature to life through a close reading of the cathedral texts of my childhood and youth. I used literature as a road map for life, as girls often do. This dynamic becomes problematic as the compelling ideology of romance channels girls narrowly toward heterosexuality and marriage. The high price that may be paid for investing in the promise of romance is examined against the backdrop of Virginia Woolf s understanding that "intellectual freedom depends on material things." The solution to these problems (if there can be said to be one) is not simply a matter of changing the stories girls read. In a rapidly changing social world the romance is increasingly fundamental to the maintenance of order, critically embedded in the workings of the economy, and a pathway into the compelling archetypal world. I interpret the current frenzy in the educational realm as 'backlash' against the great gains and newfound liberties of women and girls. I trace the twinned trajectories of girls and the women who teach them through feminist literary, philosophical, and cultural theory back to the deeply buried history of the archetypal realm to find the answers I seek. Women teaching in a 'girl-poisoning' culture can begin to mitigate the effects of that culture by listening to girls and by honouring their own memories. Using my scholarship and my life history as a template, I reinterpret the mythology of love, thereby hoping to genuinely make room in the classroom for the experiences, voices and values of women and girls.
Reader meets book, textual engagements and the genres of liminality in the English Renaissance

The purpose of this thesis is to explore how various kinds of books were marketed to readers in the early modern London book trade, especially between 1580 and 1620. I argue that publishers presented texts with a colourful range of paratextual devices, and that these devices allow insight for us today not only into the book trade but also into the psychological dynamics involved in contemporary reading. I suggest that the sort of readerly engagements which Iser and Fish find in canonical texts can also be found in the paratexts of more ordinary early modern books. I begin by situating my study within the current critical landscape. This thesis joins the trend in scholarship which has been called "New Textualism" by examining a set of pages which has never received comprehensive aesthetic attention. Next, it surveys the most important genres of the early modern paratext, and the metaphors which were used to advertise books. It goes on to explore ways in which some authors of poetry, drama and fiction observed the genres and dynamics of the paratext. Once we become aware of how important these pages were and what their function was, we can detect subtle allusions to prefatory genres in contemporary literature. The first part of the thesis thus demonstrates that front matter is literary, and the second half shows that literary texts often echo front matter in ways that have gone unnoticed. Put together, these two sections of the thesis undermine received notions of what a literary text is.
Isolation and characterization of a photoreceptor gene MPD1

The majority of genes associated with retinal degenerations are expressed specifically in photoreceptor cells. To identify novel candidate inherited retinal degeneration genes, a differential screening strategy was designed to clone genes that are photoreceptor-specific in their 'retinal' expression. In a pilot screen, 145 cDNAs from a normalized human retinal cDNA library were found to be differentially expressed. The clones were classified as putatively photoreceptor-specific within the retina and were sub-grouped based on sequence analysis into four categories; Known genes, ESTs, Novel cDNAs, and Uninformative inserts. One of the Novel cDNAs ('MPD1'), appeared to be photoreceptor-specific in its retinal expression on the basis of initial 'in situ' hybridization studies. Additional library screening identified a cDNA that was subsequently determined to be chimeric. The 5' portion was derived from a partially processed mRNA matching a predicted human ORF of unknown function, CGI-67, containing a putative Ã/ß hydrolase domain.
The role of murine fizzy-related protein in the trophoblast giant cell endocycle

We have identified and characterized the murine fizzy-related (' Fzr') gene which encodes a WD-repeat protein with a high degree of homology to its Xenopus and Drosophila homologs. 'Fzr' is expressed in post-mitotic and endoreduplicating cells of the mouse placenta as well as in differentiated Rcho-1 rodent trophoblast giant cells. In proliferating Rcho-1 stem cells, overexpression of Fzr results in exit from the mitotic cell cycle at G2/M and downregulation of cyclin B, similar to what is observed in yeast. In addition, overexpression of Fzr in Rcho-1 cells promotes differentiation to the giant cell fate. These data indicate a conserved role for Fzr in regulating exit from mitosis by modulating the levels of mitotic cyclins. Furthermore, by promoting the transition from the mitotic cell cycle to the endocycle in trophoblast giant cells, Fzr plays an important role in the development and differentiation of this unique and essential cell type.
Putting the "popular" into labour education, obstacles and opportunities in theory and practice

This thesis explores the traditions of popular education and union education with special attention to issues of racism and other oppressions. Effects of modernist thought and liberalism within some popular and union education theory and practices are interrogated. While recognizing and supporting the counter-hegemonic possibilities of popular and labour education, I also argue that power differences and oppressions can go un-addressed within groups using popular education or within union settings. Suggestions for disrupting this phenomenon are explored. Issues raised regarding popular and union education are examined in the context of the 1997 summer school of the British Columbia Hospital Employees Union. This school for 200 union activists was largely conducted in the tradition of popular education. Interviews with participants, planners and facilitators, along with examination of curriculum materials, provides a basis to explore issues of equity in a context of "popular labour education". Several programmatic suggestions are presented.
Missing in access, a feminist critique of international documents that pertain to the human right of adolescent girls to access to health services and their impact on young women in Afghanistan and in Canada

The health services and programs promoting the well-being of adolescent girls as described in international declarations, covenants and conventions that have been signed by countries around the world are not available to most young women. A feminist cultural studies approach is used to study human rights documents and two case studies that describe access to health services for girls in Afghanistan and girls in Canada. The results expose a historically produced, socially constructed and culturally defined hegemony that denies girls the human right they have to health services. The way forward requires making equity a budget issue, educating civil society and program providers about human rights law, launching a Charter Challenge, conducting gender specific research, changing the measurement of program efficacy and empowering girls to take action themselves through self-esteem building physical activity programs.
Impact of intellectual property cores on field programmable gate array designs

Intellectual Property (IP) design is a rapidly growing industry and designers and users are being challenged to develop infrastructure and standard interfaces for this new industry. This research studies the impact that Intellectual Property cores have on the design of Systems-on-Chip (SoC) implemented on Field Programmable Gate Arrays (FPGAs). To obtain an understanding of the current state of core technology, a system was built using multiple IP cores. A core was designed to learn about core design issues while the remaining cores were obtained from vendors. The results were slightly discouraging as it is not a simple process to incorporate third party cores into a design, nor was it easy to obtain cores for the system. Still, the experience has provided much insight as to what problems must be addressed in the IP industry to facilitate a design methodology that includes the use of IP. These challenges include basic concerns such as interfacing difficulties as well as documentation problems that have been grossly underestimated. Yet the issue remains: circuits are becoming too complex to custom design and achieve the desired time-to-market of a product; so how can we interface IP from vendors to a system design in a methodical and timely fashion?
Cognition and emotion, a new approach

Emotions are more cognitively complex than philosophers have typically thought. That is the simple claim I argue for in this thesis. And while it is a simple point it has profound implications. Most importantly, it means that philosophy must expand its methodology beyond conceptual analysis--its favourite method of studying the emotions--and align itself with the flourishing empirical study of emotion. In the first chapter I offer a selective history of the philosophy of emotion intended to show how philosophy's current understanding of emotion has developed. The main character here is Aristotle. His complex understanding of the emotions prefigures much of the typical modern account. He saw, for example, how emotions are intimately tied to particular classes of belief and developed a detailed formal analysis of these ties. For all the power of Aristotle's analysis, however, it does have its problems. In the second chapter I identify a modern, distorted version of Aristotle's account that I call 'hypercognitivism.' The essence of hypercognitivism is a myopic focus on emotion's cognitive elements that is, strangely, coupled with an ignorance of the complexity and variability of those elements. This ignorance, I argue, stems largely from a misguided methodological reliance on conceptual analysis that has led many philosophers to ignore what the empirical sciences tell us about emotion. This is a particularly unhappy oversight because the empirical study of emotion is currently undergoing a long overdue boom. Most excitingly, the neurosciences have begun to study the neural foundations of emotion. In the third chapter I offer a brief sketch of the picture of emotion that is emerging as a result. In particular, I focus on evidence that suggests that many of our emotions are subserved in the brain by discrete 'emotion systems.' These systems possess a range of basic cognitive capacities that are capable of operating independently of higher brain systems that mediate more complex forms of cognition. In the fourth chapter I argue that philosophy should incorporate these insights into a unique form of description that captures the contribution of these basic forms of cognition to the production of emotion.
A comparison of the molecular cytotoxic mechanisms of copper and cadium

The molecular cytotoxic mechanisms of hepatocyte cell death induced by CuCl$\sb2$ and CdCl$\sb2$ have been compared. A loss of mitochondrial membrane potential was an early event in the cytotoxic process and was also prevented by SOD, catalase, desferal, dimethyl sulfoxide and antioxidants but not caspase protease inhibitors. Both metals seem to cause cytotoxicity by inducing the apoptosis death signals as cell lysis was prevented by the apoptosis inhibitors cycloheximide, dactinomycin or a tetrapeptide caspase protease inhibitor. The major differences found between the effect of Cu and Cd on hepatocyte were that: (1) Cu but not Cd rapidly oxidized GSH which effluxed the hepatocyte likely as Cu:GSSG complex whereas Cd increased hepatocyte GSH efflux with much slower GSH oxidation. (2) Cu cytotoxicity was increased by increasing extracellular Ca$\sp{+2}$ or by the omission of Na$\sp+$ or Cl$\sp-$ from the hepatocyte suspension buffer. Cd cytotoxicity was increased by decreasing extracellular Ca$\sp{+2}$. (3) Cu but not Cd cytotoxicity was readily prevented by the endocytosis inhibitors methylamine, monensin, chloroquine and 3-methyladenine which suggests that cytotoxic Cu concentrations are stored in lysosomes and/or that ROS formed by the Cu caused a lysosomal leakage of digestive enzymes. This suggests that Cu causes the hepatocytes to activate lysosomal sphingomyelinase resulting in the formation of ceramide, or other unknown lysosomal mediators which mediate apoptosis. (Abstract shortened by UMI.)
Fine structure of the swimming paddle opener muscle and its innervation in the blue crab, Callinectes sapidus

The fifth pereiopod of the blue crab is a specialized swimming limb, the dactyl of which acts as a rowing paddle. Abduction of this paddle is brought about by contractions of the opener muscle that has assumed a specialized role as a fairly equal antagonist to the closer muscle (the adductor of the dactyl). Electron microscopic examinations of the central region of the opener muscle revealed typically slow fibres with long sarcomere lengths and a high actin to myosin ratio. Muscle fibres were highly innervated with a majority having multiple innervation sites each with an inhibitory and excitatory terminal profile. This large amount of innervation may play a role in ensuring fatigue resistance and fine control for the specialized muscle. Inhibitory terminals originated synapses that were two thirds neuromuscular, inhibiting the muscle directly, and one third axo-axonal, inhibiting the excitatory axon itself. This is an unusually high degree of presynaptic inhibition possibly associated with the fine control of the paddle limb. The overwhelming majority of synapses formed by the excitatory terminal were neuromuscular, in keeping with its primary function of making the muscle contract. A very unusual synapse was also recorded in every serially sectioned area examined: axo-axonal synapses polarized from the excitatory terminal to the inhibitory terminal, suggesting putative presynaptic excitation of the inhibitory nerve terminals. Altogether, the innervation of the blue crab swimming paddle opener muscle indicated specializations for its function as a highly active muscle rapidly contracting for prolonged periods of time.