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Postpartum depression is a serious mental illness with onset of symptoms appearing anytime within the first four months after delivery (e.g. irritability, severe sadness, profound feelings of hopelessness, etc.). Environmental toxicants are synthetic (i.e. manufactured) or naturally found chemicals that are not produced by organisms as a result of cellular metabolism (e.g. tobacco smoke, pesticides, etc.). There is limited consideration for how exposure to environmental toxicants can create adverse psychological health effects, specifically postpartum depression. The purpose of this systematic review was to determine if the literature supports a link between exposure to environmental toxicants during the prenatal/perinatal period and postpartum depression and if so, to identify whether there are specific classes of toxicants that provide a higher risk for postpartum depression. Several databases were used to search the online literature, with the following inclusion criteria: articles published in English, publication years between 1995-2018, and with women of reproductive age (15-49 years old). The article selection process comprised of screening each article by title/abstract, followed by screening those articles based on full-text. Six categories of toxicants were identified among the thirty included articles. Active/passive smoke exposure was largely found to increase the risk of developing postpartum depression; dietary supplements provided mixed results; antidepressants demonstrated preventative effects; particulate air pollution was found to be associated with postpartum depression; oral contraceptives (DMPA) exhibited an increase in postpartum depressive symptoms; and organochlorine pesticides had no associative risk. Quality assessments were performed for all of the included articles, with the majority being assessed as satisfactory. This systematic review presents as a foundation for encouraging future research to investigate the link between environment and mental health, in order to attain a greater perspective.
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Neuropeptides are central modulators of many functions including male-specific mating behaviours. Understanding how these chemical messengers modulate the neural substrates are still not well understood but remains important for biological research. In Drosophila melanogaster, two well-defined microcircuits (Longer-Mating-Duration (LMD) and Shorter-Mating-Duration (SMD)), are used to understand the underlying mechanisms of how neuropeptide interactions modulate temporal information in mating behaviours. In our study, we investigated the influence of SIFamide receptor-mediated signaling and its association to both LMD and SMD. We performed several RNAi-based screens where we identified and mapped out seven different types of neuropeptidergic neurons which were found to be important to either LMD and/or SMD. Following this analysis, we highlight three independent signaling pathways which are necessary to describe the cellular mechanics of the neuropeptides involved. Firstly, we infer that synaptic contacts between proctolin and SIFamide neurons in the subesophageal ganglion mediate inhibition in SMD whereas proctoclin as a neuropeptide modulates both LMD and SMD in a non-synaptic manner. Secondly, we describe an existing insulin-related microcircuit that is modulated by the inputs of Dimmed (DIMM), a transcription factor, through adipokinetic hormone, allatostatin A, and leucokinin to exhibit SMD. Thirdly and lastly, we discuss our interpretations of how capability neurons in the central brain resolves a potential disinhibition microcircuit in LMD via olfactory based signaling in the antennae lobe. In summary, our results contribute to establishing a model system to study neuropeptidergic microcircuits in complex mating behaviours.
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There have been significant advances in communication technologies over the last decade, such as cellular networks, Wi-Fi, and optical communication. Not only does the technology impact peoples’ everyday lives, but it also helps cities prepare for power outages by collecting and exchanging data that facilitates real-time status monitoring of transmission and distribution lines. Smart grids, contrary to the traditional utility grids, allow bi-directional flow of electricity and information, such as grid status and customer requirements, among different parties in the grid. Thus, smart grids reduce the power losses and increase the efficiency of electricity generation and distribution, as they allow for the exchange of information between subsystems. However, smart grids is not resilient under extreme conditions, particularly when the utility grid is unavailable. With the increasing penetration of the renewable energy sources (RES) in smart grids, the uncertainty of the generated power from the distributed generators (DGs) has brought new challenges to smart grids in general and smart microgrids in particular. The rapid change of the weather conditions can directly affect the amount of the generated power from RES such as wind turbine and solar panels, and thus degrading the reliability and resiliency of the smart microgrids. Therefore, new strategies and technologies to improve power reliability,sustainability, and resiliency have emerged. To this end, in this thesis, we propose a novel framework to improve the smart microgrids reliability and resiliency under severe conditions. We study the transition to the grid-connected operational mode in smart microgrids,in the absence of the utility grid, as an example of emergency case that requires fast and accurate response. We perform a comparative study to accurately predict upcoming grid-connected events using machine learning techniques. We show that decision tree models achieve the best average prediction performance. The packets that carry the occurrence time of the next grid-connected transition are considered urgent packets. Hence, we per-form an extensive study of a smart data aggregation approach that considers the priority of the data. The received smart microgrids data is clustered based on the delay-sensitivity into three groups using k-means algorithm. Our delay-aware technique successfully reduces the queuing delay by 93% for the packets of delay-sensitive (urgent) messages and the Packet Loss Rate (PLR) by 7% when compared to the benchmark where no aggregation mechanism exists prior to the small-cell base stations. As a mitigation action of the utility grid unavailability, we use the electrical vehicles (EVs) batteries as mobile storage units to cover smart microgrids power needs until the utility grid recovery. We formulate a Mixed Integer Linear Programming (MILP) model to find the best set of electrical vehicles with the objective of minimum cost. The EVs participating in the emergency power supply process are selected based on the distance and throughput performance between the base station and the EVs
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Typical Parkinson’s disease (PD) is thought to be caused by a combination of genetic and environmental factors. α-Synuclein (SNCA) is central to PD pathogenesis; however, functions of SNCA outside the brain remain largely unknown. We, and others, have found that wild-type Snca expression confers anti-microbial effects in mice by reducing the severity of viral infections. Our aim is to further characterize a role of SNCA in systemic and brain health of the host during infection. We hypothesize that SNCA plays a role in innate defenses and that SNCA gene dosage will modulate outcomes of infection in the brain following pathogen exposure. Intranasal delivery of reovirus in mouse pups causes systemic illness, leading to encephalitis. In this study, intracranial inoculations of reovirus are used to differentiate the relative contribution of Snca-mediated protection in the brain versus the periphery. Two outcomes are monitored: survival and viral titres in select organs. When comparing wild-type Snca, heterozygous, and knock-out mice, I found that Snca expression did not confer any protection with respect to survival or regarding viral brain titres. These results are paralleled by cellular overexpression models. Unexpectedly, the anti-viral property of Snca, which was previously observed systemically with three distinct dsRNA viruses, did not extend to a paradigm where neural cells were directly exposed to reovirus. These results suggest a complex, anti-viral role for Snca in host defenses that may be mediated, in part, outside the central nervous system. Future studies will address whether this occurs in peripheral neurons or cells of hematopoietic lineages.
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Ammonia electrochemical oxidation is a viable technology for power generation in fuel cells since ammonia is a versatile hydrogen carrier that possesses high energy density and hydrogen content with lower energy consumption compared to the other candidates. Pt is the most active catalyst toward ammonia oxidation reaction as shows in high activity and stability. In the present study, Pt nanoparticles (NPs) were synthesized in 4 different sizes (1.3 - 4.3 nm) dispersed on carbon support using the polyol method. The effect of particle size on the catalytic activity and reaction product distribution was evaluated. The correlation between nano-catalyst size and catalytic activity has been demonstrated in the research. Pt particle size of 1.3 nm yielded comparatively better activity although Pt 2.2 nm was more stable in addition to acceptable activity. Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) was employed to analyze the formation of reaction species in real-time when the electrooxidation was occurring. Unlike regular infrared spectroscopy, PM-IRRAS enabled us to observe oxidation species on both catalyst-electrolyte interface and bulk of the solution. N-H containing species as well as nitro compounds and azide ions were identified at individual potentials on the surface of catalysts and in the bulk of electrolyte. Furthermore, Pt and Pt-based bimetallic NPs, including PtIr and PtRu, were prepared on engineered carbon support (ECS) provided for Pt group metals (PGM) in order to improve the catalyst dispersion. In the first evaluation step, the catalytic activity was tested by electrochemical measurements which indicated that incorporation of Ir enhanced the stability of the catalyst comparing to pure Pt. Besides the stability, the addition of second metal lowered the oxidation onset potential to more negative overpotential that was verified by PM-IRRAS. The resulting current density of catalysts in various concentrations of ammonia was assessed in alkaline solution. The overall upward trend in catalytic activity for PtIr and PtRu in contrast to Pt might be due to enhanced tolerance regarding N adsorbate atoms poisoning effect that occurred by the addition of Ir and Ru. The effect of carbon supports was evaluated by making a comparison between Pt/C ECS and Pt/C (commercial Vulcan XC-72) at approximately the same size around 4.5 nm and the same metal loading. Compared to untreated carbon, the substantially higher current density associated with Pt/C ECS demonstrates the effect of the support structure on the catalytic activity of Pt NPs towards ammonia electrooxidation. Improved dispersion and enhancement of the interaction between catalyst and electrolyte can be considered for a significant difference in corresponding current densities.
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Background: A breast cancer diagnosis may interfere with personal goal-setting, goal pursuit and well-being. Understanding the factors that enable or hinder personal goal-setting and pursuit among women with breast cancer can be a useful element of patient-centred care provision. Objective: To examine the content and pursuit of, and published literature regarding, the personal goals set by women with breast cancer. Methods: Study 1 was a scoping review of the published literature on personal goal-setting by women with breast cancer. Study 2 was a mixed-methods, cohort study with women recently diagnosed with breast cancer to identify their goals, whether they were able to pursue them, and barriers and facilitators of their goals. Results: Study 1: Twelve studies were included. Eight studies included an intervention; completeness of reporting intervention elements varied widely. None of the studies used validated instruments to elicit personal goals. Study 2: Eight participants enrolled and six completed the study. Health, psychological, social, and leisure goals were commonly identified. Women were moderately successful at pursuing their important goals. Perceived enablers and barriers to goal pursuit were identified. Conclusion: Findings on personal goals and personal goal-setting interventions that could help facilitate the development or enhancement of interventions for women with breast cancer to set and pursue their important personal goals.
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Reaching with altered visual feedback of the hand’s position in a virtual environment leads to reach adaptation in the trained hand, and also in the untrained hand (Wang & Sainburg, 2002). In the current study, we asked if reach adaptation in the untrained (right) hand is due to transfer of explicit (i.e., EA; conscious strategy) and/or implicit adaptation (i.e., IA; unconscious) from the left (trained) hand, and if the transfer of EA and IA changes depending on how one is made aware of the visuomotor distortion. We further asked if EA and IA are retained in the trained and untrained hand for 24 hours. Participants (n=60) were evenly divided into 3 groups (Strategy, No-Strategy, and Control). All participants reached to visual targets while seeing a cursor on the screen that was rotated 40° clockwise relative to their hand motion. Participants in the Strategy group were instructed on how to counteract the visuomotor distortion. The No-Strategy group was not told of the upcoming visuomotor distortion but was later asked to reach while engaging in any strategy they had learned in order to assess EA. Participants in the Control group were also not told of the upcoming visuomotor distortion and were never instructed to engage in any strategy when reaching. EA and IA were assessed in both the trained and untrained hands immediately following rotated reach training, and 24 hours later by having participants reach without the cursor when instructed to: (1) aim so that your hand lands on the target (to assess IA) and (2) use what was learned during training so that the cursor lands on the target (to assess EA + IA; exception of Control group). Results revealed that the groups differed with respect to the extent of reach adaptation achieved when initially training with the rotated cursor, such that the Strategy group had greater EA and less IA compared to the No-Strategy group in the trained hand. Unexpectedly, the Control group also showed less IA compared to the No-Strategy group, but was similar to the Strategy group. For both the Strategy and No-Strategy groups, EA was transferred between hands and was retained over time. While the extent of IA varied between groups in the trained (left) hand immediately following reach training trials, significant transfer of IA was not found in any of the three groups. Retention of IA was observed in the trained hand but decayed over testing days. Together, these results suggest that while initial EA and IA in the trained hand is dependent on how one is made aware of the visuomotor distortion, transfer and retention of visuomotor adaptation is driven almost exclusively by EA, regardless of instructions provided.
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Cette thèse présente, dans un premier temps, un survol de la théorie de l’autofiction telle qu’elle a été établie par son créateur, Serge Doubrovsky, et étoffée par ses successeurs. L’analyse se base sur trois caractéristiques particulières de la vision doubrovskienne, soit l’homonymie ternaire, l’écriture et le réel. Chacune de ces caractéristiques est développée selon les éléments pertinents à ma propre création, incluant les écritures autobiographique et consonantique, le rapport au lecteur et la dualité inhérente au réel. De plus, j’examine la possibilité d’utiliser le pronom tu au lieu du je habituel dans l’autofiction, faisant appel, entre autres, aux travaux d’Émile Benveniste. Dans un deuxième temps, mon récit autofictionnel, « Avant la tuerie », explore la vie de l’autrice/narratrice/personnage, Tina Charlebois, qui doit rédiger une thèse de maîtrise pendant qu’elle ressent le poids de l’âge qui la tourmente. Parallèlement, elle se remémore des moments banaux et plus significatifs de son enfance, comme la séparation de ses parents qui est, encore aujourd’hui, un autre fardeau qu’elle traîne comme un boulet. Enfin, en troisième partie, je propose une analyse de mon autofiction en misant sur sa concordance avec les théories présentées dans la première partie de cette thèse. Je valide la triade homonymique, l’utilisation du pronom tu, l’écriture propre à l’auteur d’autofiction, le lien avec le lecteur et la présence irrévocable de la fissure dans le genre autofictionnel. Il s’agit ici d’un travail soudé par le besoin de se dépasser, de se récrire, de se redonner envie de prendre la plume.
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Background: In February 2018, Canada’s National Advisory Committee on Immunization (NACI) began recommending maternal immunization with pertussis-containing vaccine (Tetanus-diphtheria-acellular pertussis [Tdap]) during every pregnancy as a strategy to prevent pertussis infection in young infants. As a baseline for future evaluation of the NACI policy, this thesis aimed to describe the characteristics of women who received Tdap immunization during pregnancy in the pre-policy time period and assess the relationship between maternal Tdap immunization with obstetrical and perinatal outcomes. Methods: We performed a population-based retrospective cohort study of all live births in Ontario, from April 2012 to March 2017 using multiple linked provincial health administrative databases. Tdap immunization during pregnancy was ascertained using Tdap-specific immunization fee codes. We used an extended Cox regression model with a time-dependent exposure variable to estimate adjusted hazards ratios (aHR) for preterm and very preterm birth. All other outcomes (gestational hypertension, chorioamnionitis, small-for-gestational-age birth, neonatal intensive care unit admissions >24 hours, composite outcome for neonatal morbidity) were assessed using log-binomial regression to generate adjusted risk ratios (aRR). All estimates were adjusted using inverse probability of treatment weights derived from propensity scores. Results: Of the 621,903 pregnancies ending in a live birth, 11,750 (1.9%) women received Tdap during pregnancy. The maternal Tdap vaccination rate increased by 8-fold across the study time period, from 4.6 per 1000 women in fiscal-year 2012 to 39.1 per 1000 women in fiscal-year 2016. Women who were nulliparous, residing in a higher-income neighbourhood, and receiving adequate or intensive prenatal care had the highest vaccination rates. There were no significant increased risks (aHR/aRR [95% CI]) for preterm birth (0.99 [0.87-1.12]), very preterm birth (1.03 [0.71-1.50]), or small-for-gestational-age birth (0.95 [0.90-1.02]) in Tdap-exposed infants. A significant reduction in risk for neonatal hospitalization and morbidity (measured by a composite outcome) was found among exposed infants; however, these associations were attenuated following sensitivity analyses. Among Tdap-vaccinated women, compared to unvaccinated women, there was no association with chorioamnionitis (0.95 [0.79-1.15]), but a 19% lower risk of gestational hypertension was observed (0.81 [0.74-0.90]). Conclusions: We did not detect any adverse obstetrical or perinatal outcomes following Tdap vaccination during pregnancy. These results complement existing evidence that maternal Tdap vaccination is not associated with adverse outcomes in either the mother or infant. On-going evaluation in Canada is needed as Tdap coverage among pregnant women increases in the coming years.
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Murine leukemia virus (MLV), classified as a gammaretrovirus, has been studied extensively to enhance our understanding of the biology and replication of retroviral infection. Typically referred to as a simple retrovirus, its usefulness as a model is highlighted owing to its minimal genome. The genetic material for MLV was thought to only code the basic and essential defining features of a retrovirus. Through the understanding developed from the use of simple retroviruses, the clinical and research communities were immeasurably more prepared to combat the more complex and decidedly infamous human immunodeficiency virus (HIV). Interestingly, a scenario of convergent evolution has directed MLV to encode an accessory protein, termed Glycosylated Gag (gGag), that shares functionality reminiscent of several HIV proteins. Herein, I present a dissection of a novel function of this enigmatic protein, paired with an improved understanding of the biology of MLV that was revealed by the development of small particle flow cytometry performed on viruses, also known as flow virometry. Initially, we elucidated that gGag is responsible for the resistance of MLV towards the restriction factor murine APOBEC3 (mA3). I showed that even endogenous mA3 from primary cells exhibited an enhanced enzymatic activity towards MLV with mutant gGag proteins which have lost glycosylation sites. In our following study, I illustrated that these mutants displayed a reduced viral core stability, the severity of which was correlated directly with susceptibility to mA3. These results are in line with the hypothesis that viral core stability and APOBEC3-susceptibility are directly linked. Furthermore, I showed for the first time that unprocessed gGag was associated with viral particles released from producer cells in the orientation of a type I membrane protein, with the structural regions directed within the viral core. This may be the direct evidence of how gGag improves capsid stability, a mechanism which is still unresolved. On the flip side, gGag as a type II membrane protein was observed exclusively on virus-like particles devoid of detectable envelope glycoprotein (Env). This marks a potential new function for gGag in the context of infection. Given the ubiquitous necessity of an optimized core stability for any virus, combined with the overlapping function of gGag with HIV accessory proteins, continuation of this work represents an as of yet clinically unexplored avenue for the development of HIV therapeutics. At the same time, in order to characterize individual viral particles, I played an instrumental role in developing the technique of flow virometry within our core facility. I illustrated that the Env of MLV does not significantly accumulate on extracellular vesicles (EVs) and acts as an effective marker for viral particles. With this evidence in hand, the enumeration of MLV virions was made possible. By correlating this information with an absolute viral genome determination, I was able to estimate the packaging efficiency for MLV in a quantitative manner. This information suggests that roughly 80-85% of MLV particles are missing their essential genetic information. These findings may implicate the disease progression of MLV infection may be enhanced by the use of defective-interfering particles, a theory that has been suggested for HIV. This work highlighted the fact that flow virometry is uniquely capable to discriminate viral particles from other cell-derived membraned vesicles in a highly sensitive manner. Overall, my work has unveiled new complexities of a simple retrovirus, while laying the groundwork towards both diagnostics and therapeutics for the ongoing battle with HIV.
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