The dual effect of normobaric hypoxia on heart rate variability and substrate partitioning following interval cycling

Recent studies have shown the importance of the beat-by-beat changes in heart rate influenced by the autonomic nervous system (ANS), or heart rate variability (HRV). The purpose of this study was to examine the lasting effects of hypoxic exercise on HRV, and its influences on substrate usage. Results from this study could lead an increased understanding on this topic. Eight active healthy males (age: 31±11 years; height: 180±7 cm; weight: 83±8 kg; VO₂max (maximal oxygen consumption): 4.4±0.6 L•min⁻¹) underwent normoxic and hypoxic (FᵢO₂= 0.15) conditions during high-intensity interval (HIIT) cycling (70%-high interval, 35%-rest interval). Cycling intensity was determined by a peak power output cycling test. Each experimental session consisted of a basal metabolic rate determination, up to 45-minutes of HIIT cycling, and three 30-minute post-exercise metabolic rate measurements (spanning 3 hours and 15 minutes after exercise). During exercise, RPE was higher (p<0.01) and LAC (lactate) increased (p=0.001) at each point of time in hypoxia, with no change in normoxia. After hypoxic exercise, the SNS/PNS ratio (overall ANS activity) was significantly higher (p<0.01) and significantly decreased through time in both conditions (p<0.01). In addition, a significant interaction between time and conditions (p<0.02) showed a decrease in LAC concentration through time post-hypoxic exercise. The findings showed that a single bout of hypoxic exercise alters ANS activity post-exercise along with shifting substrate partitioning from glycolytic to lipolytic energy production. The significant decrease in LAC concentration post-hypoxic exercise supports the notion that hypoxic HIIT induces a greater muscle glycogen depletion leading to increased fat oxidation to sustain glycogenesis and gluconeogenesis to maintain blood glucose level during recovery.

Second-order cyclostationarity-based detection and classification of LTE SC-FDMA signals for cognitive radio

Cognitive radio (CR) was developed for utilizing the spectrum bands efficiently. Spectrum sensing and awareness represent main tasks of a CR, providing the possibility of exploiting the unused bands. In this thesis, we investigate the detection and classification of Long Term Evolution (LTE) single carrier-frequency division multiple access (SC-FDMA) signals, which are used in uplink LTE, with applications to cognitive radio. We explore the second-order cyclostationarity of the LTE SC-FDMA signals, and apply results obtained for the cyclic autocorrelation function to signal detection and classification (in other words, to spectrum sensing and awareness). The proposed detection and classification algorithms provide a very good performance under various channel conditions, with a short observation time and at low signal-to-noise ratios, with reduced complexity. The validity of the proposed algorithms is verified using signals generated and acquired by laboratory instrumentation, and the experimental results show a good match with computer simulation results.

Positive mental health in adults reporting sexual abuse in childhood

The purpose of this study was to investigate whether a history of child sexual abuse can impact Positive Mental Health in Canadian adults and how frequency of child sexual abuse as well as perceived social support impact Positive Mental Health scores for this population. Data was collected from the Canadian Community Health Survey- Mental Health 2012 and included a sample of 20,529 adults aged 18 and older, living across ten provinces. A one-way ANOVA showed a significant difference between Positive Mental Health scores for individuals reporting a history of child sexual abuse compared to those reporting no history of child sexual abuse. A regression analysis found that reported frequency of child sexual abuse did not significantly impact Positive Mental Health scores for individuals reporting child sexual abuse. It also found that perception of social support was positively related to Positive Mental Health scores and accounted for 25% of the variance in Positive Mental Health scores for individuals reporting child sexual abuse. The implications of these findings are discussed in this study.

Child anxiety, resiliency, and the FRIENDS for Life program

Anxiety disorders are the most commonly diagnosed group of mental disorders in children (Kessler et al., 2012). Resiliency, defined as a child’s ability to successfully overcome an adverse event (Newland, 2014) is believed to be comprised of protective factors such as self-esteem and positive coping strategies (Rutter, 1987). These protective factors are related to child anxiety in that their presence or absence may augment or hinder a child’s resiliency towards anxiety-provoking events and situations (Lo Casico, Guzzo, & Pace, 2013; Thorne, Andrews, & Nordstokke, 2013). The FRIENDS for Life (FFL) program is a school-based anxiety prevention program which aims to decrease anxiety and increase resiliency in 8- to 11-year-old children (Barrett & Sonderegger, 2003). Previous studies have shown FFL to be an effective tool in decreasing anxiety and increasing resiliency; however, not all previous studies have utilized control or comparison groups (Brownlee et al., 2013; Neil & Christensen 2007; Stopa, Barrett, & Golingi, 2011). Moreover, existing FRIENDS literature has not previously considered the potential role of parent anxiety in child outcomes. The present study aimed to evaluate child anxiety, resiliency, and parent anxiety in relation to the FFL program while including a no-treatment control group. It was hypothesized that child anxiety would decrease and child resiliency would increase following FFL. Results obtained from a non-identified school-based sample were not entirely consistent with predictions, such that decreases in anxiety and increases in resiliency were observed in both the experimental and control groups.

The relationship between visual acuity and conceptual tempo

The purpose of this study was to examine the relationship between visual acuity and the two components of conceptual tempo, response accuracy and response latency. Subjects were chosen at random. Each subject was then administered a test of conceptual tempo, the Matching Familiar Figures Test (MFFT) and a test of visual acuity, the Snellen. The only significant relationship found was that between response accuracy and near visual acuity. Subjects with superior visual acuity made significantly fewer errors than did those with average or inferior acuity. It was concluded that visual acuity is an important determinant of MFFT performance. Based on these results, it was recommended that further research examine the relationship between visual acuity and other psychometric measures containing a visual component.

Entre Montesquieu et l'encyclopédie. Voltaire face à l'inquisition Espagnole

Nous étudions la progression, au siècle des Lumières en France, de la critique de l'Inquisition espagnole à partir de l'oeuvre de Montesquieu, en montrant comment Voltaire, principal défenseur de la tolérance religieuse du siècle, a approfondi l'analyse de Montesquieu pour faire de l'Inquisition espagnole un modèle exemplaire du fanatisme religieux, et comment finalement Voltaire a pour sa part influencé les articles sur le sujet rédigés par Louis de Jaucourt pour l'Encyclopédie.

How does employer support and educational background effect an Ergonomics Practitioner’s awareness of the relationship between ergonomics and psychosocial hazard control?

There is a growning need to address psychological health and safety in the workplace. Ergonomics tends to be widely recognized for its physical applications, such as ¨office¨ and ¨manual materials handling¨ however the other domains of specialization of ergonomics (cognitive and organizational) appear to be less well known. This study evaluates the level of understanding that professionals who practice ergonomics have of the relation between ergonomics and the control of psychosocial hazards in the workplace. A survey was distributed to ergonomics practitioners and asked them about their awareness of the relation between ergonomics and workplace psychosocial hazard control. Ergonomists and human factors specialists demonstrated a greater awareness of this relationship than other allied occupational groups that also practice ergonomics, however they indicated that there may be difficulties in the “real world” applying these areas of knowledge into practice. Participants who demonstrated a high level of awareness of the relation between ergonomics and psychosocial hazard control demonstrated stronger organizational commitment than participants with a low awareness. Ergonomics practitioners who reported having employer support for professional development also demonstrated a higher degree of awareness of the relation between ergonomics and psychosocial hazard control, as did the professionals who had been practicing in the field the longest. This research provides some insight for professional associations for Ergonomists, employers of Ergonomists, and human resource professionals about how ergonomics practitioners perceive the ergonomics field and the profession as well as their employing organization.

Ad-atoms and their enhancement effects on Pt activity for formic acid oxidation

Formic acid oxidation has been widely studied at Pt as a model reaction to understand fundamental aspects of electrocatalytic reactions in fuel cells. Electrocatalytic oxidation of formic acid takes place through two parallel pathways (direct and indirect). The indirect pathway proceeds via CO as an intermediate, which is known to be responsible for the poisoning of Pt and its consequent decrease in activity. Surface modification of Pt with ad-atoms is known to hinder this poisoning and promote the direct pathway. The incorporation of polymers (polyaniline, polycarbazole, polyindole) as supports also increases activity. Irreversibly adsorbed Sb and Bi on Pt are known to show high electrocatalytic activity for formic acid oxidation. This work presents the dependence of Sb and Bi irreversible adsorption on immersion time, metal solution concentration and pH. The activity of Sb and Bi modified Pt was correlated against immersion time and percent coverage of Pt by ad-atoms. Polyaniline support effects in combination with a Bi modified Pt catalyst showed enhancement in oxidation current compared to Pt-Bi.

Experimental and numerical studies of hydrodynamic interaction of two bodies in waves

This thesis focuses on experimental and numerical studies of the hydrodynamic interaction between two vessels in close proximity in waves. In the model tests, two identical box-like models with round corners were used. Regular waves with the same wave steepness and different wave frequencies were generated. Six degrees of freedom body motions and wave elevations between bodies were measured in a head sea condition. Three initial gap widths were examined. In the numerical computations, a panel-free method based seakeeping program, MAPS0, and a panel method based program, WAMIT, were used for the prediction of body motions and wave elevations. The computed body motions and wave elevations were compared with experimental data.

A comparison of modality effect performance in children: how reading achievement performance is influenced by echoic memory

This study investigates if less skilled readers suffer from deficits in echoic memory, which may be responsible for limiting the progress of reading acquisition. Serial recall performance in auditory, visual, and noisy conditions was used to assess echoic memory differences between skilled and less skilled readers. Both groups showed the typical modality effect, demonstrating that each had a functioning echoic memory. Less skilled readers performed more weakly than skilled readers on noisy serial recall, suggesting that the recall of less skilled readers is more vulnerable to interference than the recall of skilled readers. Nonword repetition performance indicated that all participants had reduced recall as a function of word complexity and word length. No difference between reading groups was found on this task; however, as nonword repetition and size of modality effect did not correlate, this task may not be a measure of echoic memory.

Ritual and routine: a means of adaption

Researchers have demonstrated how engaging in rituals or ‘patterned’ behaviours can help people cope with stressful situations and significant life changes. However, limited knowledge exists on the role of ritual practices in prison and how federally incarcerated Canadian men use these rituals to deal with their imprisonment. To respond to this lacuna in the literature, transcripts from 56 semi-structured interviews with former male federal prisoners released on parole into Ontario, Canada, were analyzed for emergent themes identifying the purpose of ritual and routine practices across prisons with different security classifications. Findings reveal the effectiveness of rituals for managing and mitigating the stresses of incarceration, specifically that prisoners’ routine behaviours constitute a positive strategy of adaption to incarceration (e.g., alleviating stress and passing time) in preparation for life postincarceration (e.g., anticipatory socialization). Structural Ritualization Theory frames the analyses and implications presented in this study.

The effect of note taking on memory for details in investigative interviews

Across 3 experiments, the effect of different styles of note taking, summary and access to notes was examined for memory for the details contained in a witness interview. In Experiment 1, participants (N = 40) were asked to either take notes or listen as they watched a witness interview. In Experiment 2, participants (N = 84) were asked to either take notes in one of three ways (i.e., conventional, linear, spidergraph) or listen as they watched a witness interview. In Experiment 3, participants (N = 112) were asked to take notes using the conventional or spidergraph method of note taking while they watched a witness interview and were subsequently given an opportunity to review their notes or sit quietly. Participants were then either granted access to their notes during testing or were not provided with their notes. Results of the first two experiments revealed that note takers outperformed listeners. Experiment 2 showed that conventional note takers outperformed those who used organizational styles of note taking, and post-hoc analyses revealed that recall performance was associated with note quality. Experiment 3 showed that participants who had access to their notes performed the best. The implications of these findings for police training programs in investigative interviewing are discussed.

Homomorphic encryption and database query privacy

Homomorphic encryption is a particular type of encryption method that enables computing over encrypted data. This has a wide range of real world ramifications such as being able to blindly compute a search result sent to a remote server without revealing its content. In the first part of this thesis, we discuss how database search queries can be made secure using a homomorphic encryption scheme based on the ideas of Gahi et al. Gahi’s method is based on the integer-based fully homomorphic encryption scheme proposed by Dijk et al. We propose a new database search scheme called the Homomorphic Query Processing Scheme, which can be used with the ring-based fully homomorphic encryption scheme proposed by Braserski. In the second part of this thesis, we discuss the cybersecurity of the smart electric grid. Specifically, we use the Homomorphic Query Processing scheme to construct a keyword search technique in the smart grid. Our work is based on the Public Key Encryption with Keyword Search (PEKS) method introduced by Boneh et al. and a Multi-Key Homomorphic Encryption scheme proposed by L´opez-Alt et al. A summary of the results of this thesis (specifically the Homomorphic Query Processing Scheme) is published at the 14th Canadian Workshop on Information Theory (CWIT).