VictorJuiz/thesis huggingface dataset:
Temporally-graded Retrograde Amnesia for Cocaine Place Preference Memories following Hippocampal Lesions
Keywords: Addiction
Cocaine
Memory
Reconsolidation
Relapse
Systems Consolidation

Memory is thought to be a dynamic process, as its strength, quality and anatomical organization change as a function of time. The systems consolidation hypothesis of memory postulates that while some memories are initially dependent on hippocampus, they gradually become immune to hippocampal disruptions over time. Although this temporal gradient has been observed in many types of memories, such as contextual fear memories, little is known about the reorganization of contextual drug-associated memory. In the present study, we examined the role of hippocampus in cocaine conditioned place preference (CPP) memory at different time points after conditioning. First, we found that excitotoxic hippocampal lesions impaired recent (1 day), but not remote (30 days) cocaine CPP memory in mice, suggesting that contextual drug-associated memory reorganizes over time, and becomes independent of the hippocampus. However, this remote hippocampus independent memory was disrupted if a reminder (drug+context) was administered one day before surgery, suggesting that a reminder rendered this older memory dependent on the hippocampus. Third, overexpressing myocyte enhancer factor 2 (MEF2), a transcription factor that disrupts structural plasticity, in hippocampus blocked cocaine CPP association, suggesting that structural changes in hippocampus is required to form a contextual drug-associated memory. Together, these studies are a first step in examining whether and how context-drug memories reorganized over time. These results may be particularly important as context-drug associations are implicated in drug relapse.
Hippocampal-Neocortical Networks underlying Episodic Memory and their Clinical Relevance in Medial Temporal Lobe Epilepsy
Keywords: Autobiographical Memory
Functional Connectivity
Neuronal Networks
Resting State fMRI

The hippocampus is strongly structurally and functionally connected to one of the core resting state networks of the human brain, the Default Mode Network (DMN). In addition, regions of the DMN are often co-activated with the hippocampus during episodic autobiographical memory (AM) retrieval tasks. Patients with unilateral medial temporal lobe epilepsy (mTLE) are characterized by a reasonably focal damage to the hippocampus and a specific episodic memory deficit, therefore offering the opportunity to examine the impact of hippocampal damage on DMN connectivity and how these disruptions map onto the specific deficit in episodic memory capacity. Together, these findings led to the main focus of the current thesis; that is to examine how hippocampal-neocortical networks underlying episodic memory are affected by mTLE. The first two studies of this thesis focused on resting state DMN connectivity in patients with mTLE, and revealed that functional connectivity between both hippocampi and the posterior part of the DMN, including the posterior cingulate cortex (PCC) was indicative of episodic memory capacity in this patient population. The last two studies of this thesis focused on how the hippocampus is at the center of transient episodic AM networks. In healthy controls, we were able to show that the left hippocampus was connected to different sets of brain regions during different stages of AM retrieval, construction and elaboration. Lastly, this flexible hippocampal-neocortical interplay was hindered in patients with mTLE. Together, we conclude that DMN connectivity reflects episodic memory capacity in patients with mTLE and might be of potential use in the clinical management in this patient population. Additionally, our data provide evidence that episodic memory is supported by an extensive repertoire of flexible, transient hippocampal-neocortical networks and that these dynamic networks extend beyond the regions of the DMN centering on the hippocampus as a major episodic memory hub of the brain.
Six Feet under the Weather: The Short-Term Relationship between Synoptic Weather and Daily Mortality
Keywords: daily
Gibraltar
longitudinal
mortality
synoptic
weather

The fact that weather affects human health has been thoroughly documented. However, few studies have used longitudinal archival meteorological AND demographic information in their analyses, or addressed multiple research questions in a single location. This study investigates the effects of weather extremes, unseasonable weather, weather changes, and local winds on the rate of daily mortality in the British colony of Gibraltar. By addressing several key questions at once, the interactions between different components of the weather and their collective effects on the body can be examined, which accurately reflects the complexity of real-life conditions. Daily mortality and meteorological information was collected for the period 1859-1989. In total, 39,926 individual deaths over 44,246 days were analyzed. Daily weather was classified using the Spatial Synoptic Classification (SSC). Weather change was defined by the Euclidean distance between sequential days' weather variables. Wind direction and wind speed were used to evaluate local winds. Oppressive dry tropical and moist tropical days in the summer were associated with higher mor-tality; moist polar conditions in the winter were associated with an increase in mortality for children under 5 and males over 65. Moist tropical days in the winter were associated with decreased mortality for the entire population but increased mortality for males and females over 65 and for males aged 5-65. Moist polar days in the summer were healthy for the entire population. Days with large and small weather changes were associated with an excess of mortality compared to days of intermediate weather change. Local winds were found to be positively associated with daily mortality, although the direction of the wind was not significant. Since humans face an elevated risk of mortality during days with large or small changes in the weather, public health interventions should target not only temperature extremes, but also take the variability of the weather into account.
Metabolic Regulation of Fast- and Slow-twitch Skeletal Muscles by Estradiol and Progesterone in Females and their Impact during Ischemia
Keywords: estradiol
estrogen receptor
fiber types
ischemia
progesterone
skeletal muscle

The roles of estradiol and progesterone were investigated to determine the effect of these hormones on metabolism in skeletal muscle composed of different fiber types (slow-twitch, fast-twitch and their various sub-types) which have different metabolic properties. The metabolic implications of these sex hormones were also tested under ischemic conditions. Female Sprague-Dawley rats were ovariectomized and given one of the following for 120 days: estradiol (ET), intermittent-estradiol (IE), progesterone (P), both IE and P (IE+P), estrogen receptor (ER) antagonist ICI 182,780 (ICI), selective ER modulator Raloxifene (RLX). Key statistically significant findings included that estradiol decreased glycogen phosphorylase and phosphofructokinase activity in fast-twitch muscles with greater total fast-twitch fiber content. Progesterone decreased in vivo glycogen by 25% in slow-twitch muscles. This response was only found in fast-twitch muscles when IE+P was given. During ischemia, IE+P reduced glycogen consumption irrespective of muscle type, which was attributed to lower in vivo glycogen levels. In vivo creatine phosphate (CP) levels in females given IE+P were reduced by 25%, irrespective of muscle type. Ischemic CP consumption was decreased only in fast-twitch muscles of IE+P females who had lower in vivo CP levels. ER studies established that ICI significantly lowered in vivo CP levels by 70-80% in both fast- and slow-twitch muscles, resulting in reduced ischemic CP consumption. RLX did not appear to modulate metabolism in these studies. These results demonstrated that the principle female sex hormones are important regulators of glycogen and CP metabolism and that the ER blockade decreases CP content in skeletal muscle. Moreover, ovarian steroid hormone regulation of glycogen metabolism is muscle fiber specific, whereas that of CP metabolism is not muscle fiber specific.
New Interfaces and Applications for Digital Microfluidics with In-Line Mass Spectrometry Analysis
Keywords: Digital Microfluidics
In-Line Analysis
Mass Spectrometry

Mass Spectrometry (MS) is an indispensable tool for laboratory science, but a drawback is the laborious and time-consuming sample preparation that is often required before MS analysis. Microfluidics presents a potential solution to this problem, as it offers the benefits of reduced reagent consumption and processing times, the capacity to integrate multiple functions on a single device, and potential for automated and high-throughput analysis. Digital microfluidics (DMF) is an emerging technology that may be particularly well-equipped for the kinds of sample processing steps required for MS analysis, such as extraction, derivatization, and sample clean-up. DMF is a microscale liquid handling technique characterized by the manipulation of droplets on insulated electrode arrays. Using DMF, droplets can be made to merge, mix, split, and dispense from reservoirs. Since droplets are manipulated individually and act as discrete microreactors, DMF offers total process control. Coupling the versatility of MS analysis with DMF sample handling has been beneficial for a number of DMF-based applications, but is often limited by off-line analysis. The work described in this thesis was designed to address this problem - how to couple DMF to mass spectrometry for in-line analysis. This thesis describes three new interfaces for DMF with in-line MS analysis. First, folded polyimide nanoESI emitters were developed as a low-cost alternative to conventionally used pulled-glass capillary emitters. Folded emitters were integrated with DMF devices on a single flexible substrate to form a device for in-line sample processing and analysis that was used for real-time microscale reaction monitoring. The second interface was a paper-based monolithic device format used to couple DMF with paper spray ionization MS. The third interface was used for a new DMF-based protocol for the extraction and quantification of drugs of abuse from a dried urine matrix using pulled-glass nanoESI MS emitters. This integrated device format was used to couple DMF with a miniature mass spectrometer for portable quantitative analysis. The three complementary interfaces have potential for a wide variety of applications, and could have impact in the fields of microscale chemical synthesis and bioanalysis by providing a robust and facile means for sample processing with in-line analysis by mass spectrometry.
Verbal Transitivity Development in Russian First Language Acquisition
Keywords: L1 acquisition
Null objects
Russian
French
Syntax
Verbal transitivity

Cette thèse explore le développement de la transitivité verbale en russe L1 dans le cadre de la grammaire générative avec une attention particulière aux omissions illicites de l'objet direct, et ce en comparaison avec le développement du français L1. Les omissions optionnelles de l'objet direct dans différentes langues sont normalement étudiées dans des contextes référentiels et liées à l'acquisition du clitique accusatif (Wexler 1998 ; Hamann 2003, entre autres). Pourtant, une période d'omissions est également attestée dans les langues sans clitique, comme l'anglais (Pérez-Leroux et coll. 2008). En russe, l'objet direct non référentiel est obligatoire dans certains contextes perfectifs. Un objet lexical est requis dans ces contextes téliques, contenant une projection d'aspect (AspQ) qui permet au verbe et à l'objet de s'accorder en quantité (Borer 2005). Les résultats de notre étude expérimentale, qui s'inscrivent dans le cadre théorique du développement langagier continu (dans sa version faible), révèlent que les enfants russes de 3 à 5 ans omettent optionnellement l'objet dans ce contexte perfectif fortement transitif et que ces omissions semblent être indépendantes du développement de l'aspect. À la suite des travaux de Pérez-Leroux et coll., nous supposons que la grammaire initiale contient un objet nul par défaut (N nul) employé dans tous les contextes. Le N est compatible avec les contextes téliques au cours du développement langagier parce que cet objet nul est individué dans la grammaire des enfants. L'individuation, soit la propriété du nom d'être quantifié comme une unité, est à la base de la distinction entre les noms comptables (individués) et massifs (non individués) (Gordon 1988 ; Bloom 1994). Au cours de l'acquisition de la quantification des noms non individués, comme les noms massifs et l'objet nul N, les enfants semblent recourir à une stratégie par défaut consistant à individuer tous les types de noms (Wagner et Carey 2003 ; Barner et Snedeker 2005).
Collaborative and Independent Writing: Japanese University English Learners' Processes, Texts and Opinions
Keywords: collaborative dialogue
collaborative writing
English as a foreign language
languaging
scaffolding
sociocultural theory

This study investigated the relationships among Japanese-background university students' verbal processes while writing in English (their second language, L2), the quality of the texts they produced, and their opinions about their experiences of writing in 2 conditions: one in which learners wrote with a peer (collaborative writing), and one in which the same learners wrote alone (independent writing). Data were gathered from 20 English-major freshman students in an intact introductory academic English writing course in a Japanese university. Using sociocultural theory of mind as a framework, I analysed the learners' pair dialogues during collaborative writing and speech for self protocols during independent writing, their texts produced, and post-task stimulated recalls and interview protocols. Three major findings emerged. First, pairs and individuals alike used dialogue (with the peer and with themselves) to facilitate their composing processes and correctly resolved most linguistic problems they encountered. Compared to writing individually, pairs produced more language-related, text-related and scaffolding episodes while they interacted, and used a variety of verbal scaffolding strategies. Second, independent writing promoted more fluent written texts but not any greater communicative quality or accuracy in the compositions compared to the paired writing. Finally, most students agreed that collaborative writing offered more opportunities for learning English than independent writing did, and all students expressed their desire to write in pairs again. About 40% of the students observed that speech for self was conducive to mediating their independent writing, but a similar number of students did not think so. In sum, both collaborative and independent writing played useful but different roles in these students' L2 writing, suggesting that L2 teachers could incorporate both approaches to composing into their classrooms. Theoretically, the findings are consistent with the claim that `languaging' or dialogue (with the peer and with the self) is a source for L2 learning (Swain, 2006a).
Not a Freak Show, Growing up Gay in Rural Ontario: An Arts-informed Inquiry
Keywords: Art
Arts-Informed
Autoethnography
Gay
LGBTQ
Sexual Minority

Not a Freak Show: An Arts-informed Inquiry into Growing up Gay in Rural OntarioBy:Spencer James HarrisonDepartment of Leadership, Higher, and Adult EducationUniversity of TorontoAbstract This thesis provides a lens into the climate of growing up gay in rural Ontario in the 1960s and 1970s when there were no images, narratives, or roles models upon which to build one's identity. A full-sized painted circus tent forms the basis of the research and the accompanying written thesis is in the form of an artist's catalogue. Through these forms I present my narratives as a sexual minority and provide strategies for how the present climate of homophobia might be understood and shifted if different stories were created to challenge the oppressive ones that now surround and frame this population. To examine the phenomenon of growing up gay during this time period I began an Artist-in-Residency in a Toronto District School Board High School, where I used an autoethnographic methodology to paint and tell my own story, so I might hear it, share it, and investigate how I and others understand it. This studio provided a site where the narratives of my life, which homophobia had silenced and made invisible, could be revealed. Through the production of a major program of painting I challenged others' ideas of what growing up gay was like, I addressed a missing element of Canadian gay history, and I made methodological advancements through bringing together Arts-informed and Autoethnographic methodologies. Upon completing the painted project I wrote the major narratives that emerged from creating the studio space. The written thesis is presented in a storied form to make it accessible to a broad range of readers and to leave space for readers to consider their own stories. Through this research I came to understand how I made sense of my world, ways my community can change the narratives that are told about them through telling their own, and the value of art as a mechanism for social change. This research contributes to fields of art for social change, history of sexual and gender minority people, notions of belonging, and furthers Arts-informed and Autoethnographic methodologies.
Error-correcting Codes for Low-Delay Streaming Communications
Keywords: Burst
Isolated and Random Erasures
Erasure Channels
Error Correcting Codes
Forward Error Correction (FEC)
Low-Delay Streaming Codes
Temporally Correlated Erasures

This thesis develops a new class of error-correcting codes for low-delay streaming over packet-erasure channels. Such codes must operate sequentially on the incoming source stream, and must reconstruct each source packet within a fixed delay of T packets. We show that both the fundamental limits, as well as structural properties of such
Non-literate and low-literate mobile phone users: Do they acquire literacy?
Keywords: Adult literacy
Cell phones
International development
Literacy
mLearning
Mobile phones

To observe the effects of prolonged periods of texting on adult literacy levels, this study distributed basic mobile phones to rural adult learners on a continuum of literacy skills from non-literate to literate at an advanced level. The details of the research design were only finalized once the study had begun, and a baseline of habits of mobile phone users in the target area was established. This informed the particulars of an intervention where participants were trained on the use of mobile phones and received text messages sent by the researcher for nine months. The contents of the text messages were news clips curated by the researcher on a variety of topics, including sports, politics and science. The participants were prompted with questions and requests for comments on the news clips. Seven of the total nine participants completed the study - a relatively high percentage given the high attrition rates of traditional adult literacy initiatives (Askov, 2000) - indicating that ownership of the mobile phones upon conclusion of the study may have acted as an incentive (motivation) for completion for the participants. In post-test literacy scores, the participants with the fewest years of education - three in total - outperformed other participants in overall gains in the reading and writing sections of the literacy tests. Six of the seven participants revealed changes in their engagement with literacy events and practices, and several participants recalled engaging in collaborative learning with peers to review texted news clips. Others reported re-engaging with traditional literacy media, including newspapers and children's textbooks to supplement their texting abilities. One participant, essentially non-literate at the beginning of the intervention, had gained rudimentary reading skills by the end.
Gaussian Process Regression with Heteroscedastic Residuals and Fast MCMC Methods
Keywords: Bayesian Analysis
Gaussian Process
Heteroscedasticity
Markov Chain Monte Carlo

Gaussian Process (GP) regression models typically assume that residuals are Gaussian and have the same variance for all observations. However, applications with input-dependent noise (heteroscedastic residuals) frequently arise in practice, as do applications in which the residuals do not have a Gaussian distribution. In this thesis, we propose a GP regression model with a latent variable that serves as an additional unobserved covariate for the regression. This model (which we call GPLC) allows for heteroscedasticity since it allows the function to have a changing partial derivative with respect to this unobserved covariate. With a suitable covariance function, our GPLC model can handle (a) Gaussian residuals with input-dependent variance, or (b) non-Gaussian residuals with input-dependent variance, or (c) Gaussian residuals with constant variance. We compare our model, using synthetic datasets, with a model proposed by Goldberg, Williams and Bishop (1998), which we refer to as GPLV, which only deals with case (a), as well as a standard GP model which can handle only case (c). Markov Chain Monte Carlo methods are developed for the GPLC and GPLV models. Experiments show that when the data isheteroscedastic, both GPLC and GPLV give better results (smaller mean squared error and smaller negative log-probability density) than standard GP regression. In addition, if we do not assume Gaussian residuals, our GPLC model (as in case (b) above) is still generally nearly as good as GPLV when the residuals are in fact Gaussian. When the residuals are non-Gaussian, our GPLC model is better than GPLV.Evaluating the posterior probability density function is the most costly operation when Markov Chain Monte Carlo (MCMC) is applied to many Bayesian inference problems. For GP models, computing the posterior density involves computing the covariance matrix, and then inverting the covariance matrix. The computation time for computingthe covariance matrix is proportional to pn2, and for the inversion is proportional to n3, where p is the number of covariates and n is the number of training cases. We introduce MCMC methods based on the "temporary mapping and caching" framework (Neal, 2006), using a fast approximation, *, as the distribution needed to construct thetemporary space. We propose two implementations under this scheme: "mapping to a discretizing chain", and "mapping with tempered transitions", both of which are exactly correct MCMC methods for sampling , even though their transitions are constructed using an approximation. These methods are equivalent when their tuning parameters are set at the simplest values, but differ in general. We compare how well these methods work when using several approximations, nding on synthetic datasets that a * based on the "Subset of Data" (SOD) method is almost always more efficient than standard MCMC using only On some datasets, a more sophisticated * based on the "Nystrom-Cholesky" method works better than SOD.