Health (Faculty of)

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The Faculty was known as the Faculty of Applied Health Sciences prior to its name change in January 2021.

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A psychometric evaluation and application of a measure of food literacy among young adults
(University of Waterloo, 2024-11-11) Holmes, Martin
Background: Food literacy is an emerging study area encompassing the knowledge, skills, and attitudes required to navigate dynamic food systems. Food literacy has been suggested as a potential leverage point for improving diet quality and health outcomes. The emerging adult population, facing unique dietary and life transitions, is highlighted as an important group in public health research. Following calls for standard and well-evaluated measures of food literacy, a collaborative working group of public health nutrition practitioners in Ontario, Canada, led the development of a comprehensive food literacy measure, the FLit50, for use with young adults. To support the broad use of the measure in public health practice, assessment of the construct validity of the FLit50 and the development of a shortened version were desired by the public health nutrition practitioners. Objectives: The objectives of this dissertation were to: (1) evaluate the construct validity of the FLit50 measure among post-secondary students (Chapter 5); (2) analyze the characteristics of the FLit50 items to facilitate the development and evaluation of a shortened measure (Chapter 6); and (3) explore the demographic, income adequacy, studentship, and health correlates of food literacy among post-secondary students (Chapter 7). This work was undertaken in collaboration with the public health nutrition practitioners. Methods and results: The first study (Chapter 5) drew upon data from 457 post-secondary students in Ontario, Canada, to evaluate the measure's construct validity by assessing whether it could differentiate between groups hypothesized to have differences in food literacy. The FLit50 showed adequate construct validity, evidenced by higher median food literacy scores among students in food and nutrition programs (KW χ2) = 108, p < 0.001), women (KW χ2= 49.2, p < 0.001), those with adequate health literacy (KW χ2 = 20.6, p < 0.001), those with higher general health (KW χ2 = 49.5, p < 0.001), those with higher mental health (KW χ2 = 17.4, p < 0.001), and those experiencing food security in the past 12 months (KW χ2 = 21.9, p < 0.001), as hypothesized. No differences were observed by age (KW χ2 = 5.24, p = 0.63) or perceived income adequacy (KW χ2 = 4.21, p = 0.38). Differences in group means were observed as hypothesized for scores on items reflecting the underlying domains of food and nutrition knowledge and self-efficacy and confidence, but not food skills or ecological factors. The second study (Chapter 6) involved the application of the 2-parameter Item Response Theory, using data from postsecondary students (n=457) along with data collected from young adults across Canada during the initial development of the measure (n=351). Item difficulty (mean= -1.72 SD from the sample’s average food literacy ability level, range: -3.64 to 3.05 SD) and item discrimination (mean= 1.78, range: 0.33 to 8.43) characteristics were estimated for items on the FLit50. The parameters informed discussions with the public health nutrition practitioner partners to select sixteen items for inclusion in the shortened measure, the FLit16. The correlation coefficient between scores on the FLit50 and the FLit16 was estimated, and whether the FLit16 could differentiate among groups hypothesized to have different levels of food literacy, as per study 1, was examined. Scores from the two versions of the measure were strongly and positively correlated (Rho = 0.87, p < 0.01) and the short measure was able to differentiate among groups, consistent with the full measure. The third study (Chapter 7) drew upon data from the sample of postsecondary students to explore associations between demographic, income, studentship, and health characteristics, identified a priori based on the emerging food literacy literature, and food literacy scores using multiple linear regression analysis. Data from 413 students were included in these analyses after accounting for missing data on the characteristics of interest. Food literacy was assessed using the FLit50 measure, with a mean score of 42 of 49 points. Adjusting for other characteristics, food literacy was higher among women compared to men (β = 2.509, p < 0.001) and those who reported positive or neutral general health (β = 1.743, p < 0.001). Food literacy was lower among individuals identifying as East/Southeast Asian (β = -2.036, p < 0.001), South Asian (β = -2.409, p < 0.001), and other racial/ethnic identities (β = -1.568, p = 0.005) compared to those identifying as White. Food literacy was also lower among those who lived on-campus (β = -1.457, p = 0.073) and those experiencing food insecurity (β = -1.274, p = 0.004). Food literacy scores did not differ by age, income adequacy, domestic or international studentship, whether students attended college or university, household composition, or self-reported mental health status. The regression analysis yielded an R2 of 0.403, indicating that 40% of the variance in food literacy scores was explained by this model, with an overall significance of F(15, 396 DF) = 17.79, p < 0.001. Conclusions: This dissertation continues the work of the collaboration of public health nutritionists by furthering two of its main aims: establishing the construct validity of the FLit50 and developing a shortened measure that demonstrates construct validity. The availability of two well-evaluated measures presents opportunities to better understand and monitor food literacy in emerging adults and assess associations with factors such as diet quality.
Aboriginal participation in sport: Critical issues of race, culture and power.
(University of Waterloo, 2009-10-28T19:11:54Z) Henhawk, Daniel
This study is a qualitative examination of my lived experiences and the lived experiences of my immediate family in sport. Using critical race theory (CRT) as my guiding theoretical framework, this research project answers Denzin’s (2003) call to advance “a radical performative social science” that “confront[s] and transcend[s] the problems surrounding the colour line in the 21st century” (p.5). As such, the purpose of this project was to explore issues of race, culture and power within our lived sport experiences and to present these experiences in such way so as to unpack the tensions associated with being an Aboriginal person living in today’s Canadian society.
Acceptability of the interRAI Check-Up Self-Report Comprehensive Geriatric Assessment (CGA) Tool: Evaluating Check-Up Acceptability in Assessing Care Needs of Older Adults with Human Immunodeficiency Virus (HIV) in Kampala District of Uganda
(University of Waterloo, 2022-09-02) Kroetsch, Brittany
Background: The Ugandan healthcare system is ill-equipped to manage the emerging medical and social needs of its aging population. With the high burden of human immunodeficiency virus (HIV), food insecurity, and the erosion of support systems, older adults are limited in their ability to maintain physical and emotional health and well-being. High levels of impairment in activities of daily living, cognition, and frailty associated with HIV coupled with increased multimorbidity for aging Ugandans calls for the revision of healthcare policies and evidence-informed practice. Objectives: This thesis aimed to estimate the association between HIV status and (i) activities of daily living, (ii) cognitive function, (iii) health stability, and (iv) clinical frailty in older persons living in Kampala, Uganda using the interRAI Check-Up self-report assessment instrument. Additionally, this thesis aimed to (v) evaluate assessment acceptability to inform healthcare system planning and care practices. Methods: A mixed methods design was employed. In Phase One, HIV-positive and negative older adults aged ≥60 years were assessed using the interRAI Check-Up self-report in the Nakawa division of Kampala. Patient characteristics were summarized with descriptive statistics, and a logistic regression analysis was used to identify differences in activities of daily living, cognitive function, health stability, and frailty of older persons in the study. In Phase Two, key informant interviews with service providers at the Reach Out Mbuya Community Health Initiative were held to characterize the acceptability of the Check-Up in the Ugandan setting and to explore perceptions of its use. Results: In Phase One, 130 Check-Up assessments were obtained for older persons in the community. HIV status was found to not be statistically significantly associated with the outcomes of interest and age was found to be positively associated with outcome scores for activities of daily living, cognitive performance, and frailty. However, age was not found to be associated with health stability. In Phase Two, 12 interviews were held with service providers at the Reach Out Mbuya Community Health Initiative. The Check-Up was found to be acceptable for use in the Ugandan setting, with minor gaps identified for coverage of economic stability, food security, living arrangement, and the physical environment. Further, challenges with languages offered, the technology required, and length of time to complete was discussed. Discussion: Findings of age-related associations for activities of daily living, cognitive performance, and frailty were conclusive with expectations for the trajectory of health throughout the aging process. Similarities across HIV-positive and negative participants are attributed to participant age, low study sample size, viral suppression, and healthcare service utilization. For Check-Up use in the Ugandan setting, several recommendations are made to address identified gaps including question modifications, further translations, provision of additional tablets, and granted permissions to RAIsoft. Next, capacity training for Check-Up use by service providers is introduced, including the need for sensitization of gender differences and appropriate structuring of assessors in the field. Lastly, a theoretical framework assessment revealed barriers in the ability of the Theoretical Framework of Acceptability to identify key gender and socio-cultural differences in intervention recipients and deliverers. Implications: This thesis provided important information for describing the needs of aging Ugandans and insight into how a standardized instrument can help to support the development of a geriatric-friendly healthcare system across the nation. This was an important step in establishing an interRAI community of practice in East Africa.
Acceptance and Usage of Smart Wearable Devices in Canadian Older Adults
(University of Waterloo, 2017-05-09) Puri, Arjun
Background: As the Canadian older adult population grows rapidly, emerging solutions and technologies that have the potential to enable aging-in-place are garnering more attention from developers, public policy makers and international organizations. One category of emerging technologies is smart wearable devices; however, their acceptance is low. In addition, information about Canadian older adults’ attitudes toward smart wearable devices is scarce and requires additional exploration. Objective: To explore Canadian older adults’ attitudes toward and acceptance of two smart wearable devices, the Microsoft Band and the Xiaomi Mi Band. Methods: A mixed methods design was used to capture descriptive statistics and to explore participant’s attitudes and experiences. Twenty older adults aged 55 or older were recruited from the cities of Kitchener-Waterloo, Cambridge, and Guelph, Ontario. Participants were invited to use two different smart wearable devices, the Microsoft Band and the Xiaomi Mi Band, for 21 days each. Questionnaires were used to capture descriptive statistics, acceptance and explore attitudes towards smart wearable devices. Subsequently, semi-structured interviews were conducted with a purposively selected sample of four participants (three females and one male) and a content analysis was performed. Results: Older adults in the study ranged in age from 55-84 (mean = 64). Gender distribution was reasonably balanced and the sample had high levels of education. Older adults were willing to accept smart wearable devices and believed continuous health monitoring could be helpful. Older adults in the sample also had high levels of technology experience and smart wearable devices awareness. Older adults believed a smart wearable device should cost between $0-$200. The Mi Band gained higher levels of acceptance (80% accepted) compared to the Microsoft Band (45% accepted). Most older adults used each smart wearable device for the entire 21-day testing period. Quantitative analysis revealed smart wearable device acceptance was associated with facilitating conditions, perceived risks and equipment characteristics. Content analysis resulted in the formation of four main themes regarding older adult’s attitudes toward and acceptance of smart wearable devices: 1) smartphones as facilitators of smart wearable devices, 2) privacy concerns, 3) subjective norm and facilitating conditions, and 4) smart wearable device equipment characteristics. Conclusion: This exploratory study contributes to addressing the scarcity of research that explores Canadian older adults’ attitudes toward and acceptance of smart wearable devices. Findings from this study suggest that older adults are willing to accept smart wearable devices and find them useful. However, lack of knowledge and experience in operating smartphones, reduced facilitating conditions, and unfavorable equipment characteristics (regarding comfort, aesthetics, and battery life) may deter the usage and acceptance of wearable devices. Privacy concerns of using smart wearables were not impactful on acceptance for older adults in the sample. These findings add to emerging research that investigates acceptance and factors that may influence acceptance of smart wearable devices among older adults.
Accessing Indigenous Foods in Urban Northwestern Ontario: Women’s Stories of Indigenous Food Sovereignty and Resistance to Policy
(University of Waterloo, 2021-04-28) Phillipps, Breanna
Indigenous populations living in urban northern Ontario have been repeatedly ignored in research regarding Indigenous Peoples food insecurity and food systems, despite the large proportion of Indigenous Peoples living in the region and the unique challenges of the urban northern food environment. The purpose of this thesis is to explore and better understand how Indigenous Peoples in the urban northwestern Ontario service hubs of Sioux Lookout and Thunder Bay access Indigenous foods and the relationship of Indigenous food to their food security and Indigenous food sovereignty. The methodology of this project is based upon on the principles of community-based participatory research, intersectional feminist theory, and the USAI Framework (utility, self-voicing, access, and inter-relationality). Data were collected in open-ended interviews with stakeholders from three groups across the two cities (1) Indigenous female community members (n=6), (2) non-Indigenous staff of Indigenous-serving organizations (n=6), and (3) policymakers (i.e. those related to wild food policy or its implementation)(n=6). Two analyses were conducted. First, a thematic analysis of interview data from Indigenous community members and non-Indigenous staff of Indigenous-serving organizations characterized the impact of place and urbanicity on accessing Indigenous foods in both urban northwestern Ontario cities. Second, an Intersectionality-Based Policy Analysis framework was applied to analyze interview data from the entire sample which illuminated how the provincial and federal policy contexts have historically and continue to impact Indigenous women and their communities’ experiences of accessing wild foods in urban northwestern Ontario. Both place and urbanicity are central to how Indigenous populations in these towns harvest, share, and consume their Indigenous foods. On the community and individual levels, Indigenous Peoples in these towns are often in situations of food insecurity due to financial, geography, and policy barriers. Participants highlighted the abundance of ways that Indigenous food sovereignty is being expressed. Building food networks and sharing practices amongst friends, family, and broader communities (both inside and outside the city) was central to promoting access to Indigenous food for Indigenous Peoples in this study. Indigenous women pointed to colonial policies which make it impossible for most people to harvest in a self-determined way; thus, resistance is necessary. We found that stakeholder groups defined the policy problem differently and brought different values to their place in the systems which impede or facilitate access to wild foods. There was an acknowledgment of the conflict of Western food safety and natural resource management principles with Indigenous rights and Indigenous food sovereignty in theory and application. Implementation of food and natural resource policy is often unclear due to the tensions of government jurisdiction and the erasure of Indigenous Peoples’ experiences within Canadian cities. This thesis reiterates that Indigenous-led and culturally safe collaborations between the Indigenous community and other organizations are critical to improving Indigenous food sovereignty in these urban settings. Illuminating the non-Indigenous actors’ understandings of Indigenous Peoples' food security and sovereignty in urban settings is key as they hold power in colonial institutions. There is a continued need for Indigenous distinctions-based and intersectional approaches in all policy at all levels – from the federal to the institutional.
Accuracy of Parental Reporting of Preschoolers’ Dietary Intake Using an Online Self-Administered 24-h Recall
(MDPI, 2018-07-29) Wallace, Angela; Kirkpatrick, Sharon I.; Darlington, Gerarda; Haines, Jess
Parents are typically relied upon to report young children’s dietary intake. However, there has been limited research assessing the accuracy of such reports captured using novel dietary assessment tools. The purpose of the current study was to assess the validity of the web-based Automated Self-Administered 24-h Dietary Assessment Tool (ASA24-Canada) for capturing dietary intake among children aged two-five years (n = 40), using parental proxy reporting. The study was conducted in a daycare setting, allowing for standardization of foods and drinks offered and direct observation of intake. Parental-reported intake was compared to true intake for lunch and dinner, as well as an afternoon snack, on a single day. Each eating occasion, including plate waste, was unobtrusively documented. Parents were not present for lunch or the afternoon snack, but joined their children at the daycare centre for the dinner meal. The following day, parents reported their children’s intake from the previous 24-h period using ASA24-Canada. For the eating occasions assessed, parents reported exact or close matches for 79.2% (82.3% for lunch, 81.2% for the snack, and 77.4% for dinner) of the foods and beverages truly consumed by children. Estimates of intake for energy and macronutrients examined (carbohydrates, fat, and protein) based on parental reports were higher than those based on true (observed) intake. Our findings suggest that parents are able to report what their preschool children eat and drink relatively accurately. However, the accuracy of portion size estimates is low. Strategies to enhance portion size reporting are needed to improve parental proxy reporting.
Accuracy of self-reported intake of signature foods in a school meal intervention study: comparison between control and intervention period
(Cambridge University Press, 2015-08-28) Biltoft-Jensen, Anja; Damsgaard, Camilla T.; Andersen, Rikke; Ygil, Karin Hess; Andersen, Elisabeth Wreford; Ege, Majken; Christensen, Tue; Sorensen, Louise Bergmann; Stark, Ken; Tetens, Inge; Thorsen, Anne-Vibeke
Bias in self-reported dietary intake is important when evaluating the effect of dietary interventions, particularly for intervention foods. However, few have investigated this in children, and none have investigated the reporting accuracy of fish intake in children using biomarkers. In a Danish school meal study, 8- to 11-year-old children (n 834) were served the New Nordic Diet (NND) for lunch. The present study examined the accuracy of self-reported intake of signature foods (berries, cabbage, root vegetables, legumes, herbs, potatoes, wild plants, mushrooms, nuts and fish) characterising the NND. Children, assisted by parents, self-reported their diet in a Web-based Dietary Assessment Software for Children during the intervention and control (packed lunch) periods. The reported fish intake by children was compared with their ranking according to fasting whole-blood EPA and DHA concentration and weight percentage using the Spearman correlations and cross-classification. Direct observation of school lunch intake (n 193) was used to score the accuracy of food-reporting as matches, intrusions, omissions and faults. The reporting of all lunch foods had higher percentage of matches compared with the reporting of signature foods in both periods, and the accuracy was higher during the control period compared with the intervention period. Both Spearman's rank correlations and linear mixed models demonstrated positive associations between EPA + DHA and reported fish intake. The direct observations showed that both reported and real intake of signature foods did increase during the intervention period. In conclusion, the self-reported data represented a true increase in the intake of signature foods and can be used to examine dietary intervention effects.
ACL Injury Mechanisms and the Kinetic Chain Linkage: The effect of proximal joint stiffness on ACL injury risk.
(University of Waterloo, 2016-08-30) Cannon, Jordan
Recent literature has suggested that core and gluteal neuromuscular deficits are involved in the mechanism of non-contact ACL injury. Several research groups have identified dynamic valgus of the lower extremity to be an injurious posture that is predictive of future non-contact ACL injury risk. Aberrant kinematics of segments proximally in the kinetic chain, namely the trunk and hip, have also been observed to drive dynamic valgus during dynamic activities. Comprehensive investigation of the neuromuscular deficits postulated as the mechanism of injurious mechanics are lacking in the literature. Given that certain motions can be created by infinite muscle activation combinations, and that muscle activation contributes both force and controlling stiffness, this work aims to characterise any such deficits by examining the ability to modulate proximal joint stiffness to dynamically control distal segments of the kinetic chain. Three-dimensional lumbar spine stiffness and hip stiffness were quantified in participants deemed as ‘high valgus’ and ‘low valgus’ based on their frontal plane knee displacement during each task. The risk of non-contact ACL damage is highest among active females, justifying their choice to study. Eighteen female participants completed drop vertical jump (DVJ), stop jump (SJ), single leg drop (SLD) and single leg crossover drop (SLCD) tasks in order to measure medial knee displacement and associated proximal joint stiffness values. It was hypothesized that those with high valgus would not generate sufficient joint rotational stiffness at the lumbar spine, hip, or both, and thus aberrant kinematics and the injurious dynamic valgus motion would result. Those who were able to develop sufficient stiffness at the lumbar spine and hip had greater control over the kinetic chain and in doing so reduced dynamic valgus and likely their risk of future ACL injury. However, variance within subjects was found, specifically the same person would show a valgus landing on one trial, but not on another. This necessitated a change in analysis to one considering the landings as case studies, and groupings of landings by whether valgus occurred or not, rather than by subjects. This was an unexpected, and therefore exciting part of the thesis journey. The results here provide insight into the motor control component of avoiding dynamic valgus and is the first work to confirm, and specifically characterize, a neuromuscular deficit at the core or hip. That deficit appears to be an inability to generate sufficient joint rotational stiffness in order to control the linkage. Given this insight, appropriate interventions and training programs may be designed to reduce one’s risk of ACL injury.
Activated Motivation: An Opportunity for HCI Research?
(University of Waterloo, 2022-02-24) Wallace, James
Self-Determination Theory [7, 13, 14] is a decades-old, widely-validated macro-theory that describes human motivation. Generally, it defines motivation on a spectrum ranging from amotivation, or a lack of motivation, to extrinsic motivation driven by external factors like rewards, to intrinsic motivation associated with one’s internal enjoyment or interest. Moreover, the theory establishes the benefits of more internal forms of motivation: individuals acting with internal forms of motivation will tend to feel more open and curious, be more persistent, and are more likely to succeed at difficult tasks [8, 13, 14]. Indeed, these concepts have been widely validated, and have been shown to provide a practical framework for technology design [9]. However, researchers have also argued that current engagement with the theory is shallow [11, 12], particularly some of the concepts described in Self-Determination Theory’s ‘micro-theories’ [9].
Acute Cardiac Responses to Respiratory Muscle Unloading at Different Exercise Intensities
(University of Waterloo, 2022-08-29) Angus, Sarah
Respiration is accomplished by alterations in intrathoracic pressure (ITP) and has physiological implications on the heart. For example, the negative ITP during inspiration is transmitted to the right atrium, which augments venous return, preload, stroke volume (SV), and cardiac output (Q). We sought to determine the impact of respiration on Q during semi-supine cycle exercise by using a proportional assist ventilator to attenuate ITP changes and the work of breathing (Wb). Thirteen healthy participants (6 females) completed three discrete exercise trials at 30%, 60% and 80% peak power (Wmax) with unloaded and spontaneous breathing. Intrathoracic and intraabdominal pressure were measured with balloon catheters placed in the esophagus and stomach. Stroke volume was determined via echocardiography and the Simpson’s biplane method. An electrocardiogram measured heart rate (HR) and a customized metabolic cart measured ventilatory and mixed expired variables such as ventilation and oxygen consumption (V̇O2). Mean esophageal pressure was greater during unloaded relative to spontaneous breathing at all exercise intensities (p<0.0001). Esophageal pressure swings per breath (between spontaneous and unloaded breathing) were different at 30%, 60% and 80%; (-3.5±3.4 vs. -6.8±6.4 vs. -11.9±7.9 cmH2O, respectively (p=0.01). However, the decrease in Wb was not different between exercise intensities (39±22 vs. 46±14 vs. 51±14% from spontaneous breathing for 30%, 60%, and 80%Wmax, respectively, all p>0.05). Cardiac output decreased during unloaded breathing by -1.2±1.3 vs. -1.7±1.4 vs. -1.8±2.0 L min-1 from spontaneous breathing at 30%, 60% and 80%Wmax, respectively (all p<0.05). Heart rate decreased during unloaded breathing by -2±3 vs. -6±4 bpm at 60% and 80%Wmax, respectively (both p<0.05), with no change at 30%Wmax (p=0.2). Stroke volume decreased during unloaded breathing by -10.7±11.2 vs. -10.1±10.2 vs. -8.0±12.3 mL from spontaneous breathing at 30%, 60% and 80%Wmax, respectively (all p<0.05). Oxygen consumption decreased during unloaded compared to spontaneous breathing at 80%Wmax (2.5±0.6 vs. 2.6±0.7 L min-1, p=0.002) with no change at 30% and 60%Wmax (both p>0.05). In summary, attenuating ITP swings resulted in a reduction in Q at all exercise intensities. At 30%Wmax, the decrease in Q may be due to a reduction in SV. At 60%Wmax, Q decreases likely because of a reduction in SV and HR. At 80%Wmax, Q may decrease due reductions in SV, HR and V̇O2. In conclusion, the normally occurring swings in ITP developed during spontaneous breathing is helpful for maintaining cardiac function during exercise.
The Acute Effect of Exercise Intensity on Cognitive Function
(University of Waterloo, 2016-08-30) Wikkerink, Spencer
Recent research has found that regular exercise has a positive effect on cognitive function. Some studies indicate that even an acute session of exercise has a slight positive effect on cognitive function, though factors moderating this effect have not been thoroughly examined. Exercise intensity and timing of cognitive assessment may have an interactive effect on cognitive changes after exercise. Previous research suggests that moderate intensity exercise has the most consistent benefit to cognitive function. In contrast, studies find positive, negative, or null effects to cognitive function after high intensity exercise, where the timing of the post-exercise assessments may account for the observed differences. Since high-intensity interval training (HIIT) is an increasingly popular form of exercise due to equal or greater cardiovascular adaptation for reduced exercise time, understanding its cognitive effects is of interest. The primary objective of the study was to compare the cognitive effects of an acute bout of HIIT to both moderate intensity continuous training (MCT) and rest. The secondary objective was to compare the timeline of the cognitive effects between these three sessions. Twenty-two participants performed 28.5min of HIIT, MCT, and rest on three separate days, each 2 weeks apart. The rest session was performed first and the subsequent exercise sessions were randomized. Cognitive function was assessed using a modified Flanker task with concurrent electroencephalography (EEG) before and 0, 15, 30, and 45min post-intervention. The hypothesis that cognitive function would improve after MCT and HIIT was not supported. Though there was some variability in cognitive function post-exercise, cognitive function was not significantly different before to after exercise or in comparison to the rest session. However, measures of cognitive function were often better prior to the exercise sessions than before exercise, possibly due to an anticipatory effect prior to exercise or learning carry-over after the rest session, which complicated interpretation of results. Of note, only a small number of prior studies included a baseline assessment of cognitive function in each session. Future research should examine the influence of the anticipation of exercise on cognitive function to better understand whether it is the psychological or physical stress imposed by exercise that enhances cognitive function.
Acute effects of aerobic exercise on cognitive function in individuals with Parkinson’s disease
(Elsevier, 2018-04-03) Silveira, Carolina R. A.; Roy, Eric A.; Almeida, Quincy J.
Deficits in executive functions are highly prevalent in Parkinson’s disease (PD). Although chronic physical exercise has been shown to improve executive functions in PD, evidence of acute exercise effects is limited. This study aimed to evaluate the effects of an acute bout of exercise on cognitive processes underlying executive functions in PD. Twenty individuals with PD were assessed in both a Control and an Exercise conditions. In each condition, individuals started performing a simple and a choice reaction time (RT) task. Subsequently, participants were asked to sit on a cycle ergometer (Control) or cycle (Exercise) for 20 min in counterbalanced order. Participants were asked to repeat both reaction time tasks after 15-min rest period in both conditions. While no differences were found in simple RT, participants showed faster choice RT post Exercise as well as Control conditions (p = .012). Participants had slower choice RT for target stimulus compared to non-target stimuli irrespective of time or experimental condition (p < .001). There was no change in accuracy following experimental conditions. Results suggest that individuals with PD may not respond behaviourally to a single bout of exercise. The lack of selective effects of exercise on cognition suggests that practice effects may have influenced previous research. Future studies should assess whether neurophysiological changes might occur after an acute bout of exercise in PD.
Acute Regulation of Na+-K+-ATPase Activity in Skeletal Muscles of Different Fibre Type Composition in Response to Insulin Exposure
(University of Waterloo, 2008-01-09T19:00:18Z) Foley, Kevin Patrick
The Na+-K+-ATPase (pump) is a transmembrane, multi-subunit (α and β) protein that is expressed in all cells, and particularly in skeletal muscle cells. In one cycle, it pumps 3 Na+ ions out of the cell and 2 K+ ions into the cell at the expense of 1 ATP molecule. This enzyme is responsible for maintaining muscle cell excitability. This is of particular importance during contractile activity, when the flux of Na+ and K+ across the cell membrane is high. The activity of the Na+-K+-ATPase is highly regulated and very responsive to hormonal stimuli. Previous research has shown that 20-30 min insulin exposure in vivo induces the translocation of pumps from intracellular stores to the plasma membrane. However, no study has examined the catalytic properties of this enzyme in response to short insulin exposures. The objective of this study was to investigate the response of the Na+-K+-ATPase to short insulin incubation in vitro in muscles of different fibre type. It was hypothesized that the short insulin treatment would result in an increase in pump activity, not only through translocation but also increased intrinsic activity. Using an in vitro model, rat soleus (Sol), red gastrocnemius (RG), and white gastrocnemius (WG) muscle homogenates were incubated at 37°C for 5 min with and without 75μM insulin (Ins). Next, in order to separate mechanisms of translocation and intrinsic activation, the plasma (SLP) and endosomal (EN) membranes were separated through a fractionation procedure. This allowed the investigation of insulin-induced increases in intrinsic activity in SLP and EN fractions of Na+-K+-ATPase; SLP and EN (non-treated) membranes were incubated at 37°C for 5 min with and without 75μM insulin. Lastly, muscle homogenates were insulin-treated for 5 min at 37°C with 625μM insulin prior to fractionation. These SLP and EN fractions (insulin-treated) were then incubated at 37°C for 5 min with and without 75μM insulin. Na+-K+-ATPase maximal activity (Vmax, mmol•mg prot-1•h-1) and km (substrate affinity), α2 content, and tyrosine phosphorylation (Tyr-P) were probed. It was found that insulin increased Vmax (P<0.05) in Sol and RG, but not WG, homogenates (Con vs Ins, Sol=221±17 vs 256±21; RG=190±14 vs 256±18; WG=104±4.6 vs 99±1.8). In non-treated fractions, insulin increased Vmax (P<0.05) in Sol and RG SLP fractions (Con vs Ins, Sol=1710±186 vs 1970±231; RG=1476±128 vs 1655±139). A main effect, Con
Acute Regulation of Vascular Tone by AMP-activated Protein Kinase in Arteries of Healthy, Hypertensive and Aged Rats
(University of Waterloo, 2011-12-21T16:15:00Z) Ford, Rebecca Jill
Background, Rationale and General Purpose: Several seminal observations suggest that AMPK mediates vascular tone: 1) in endothelial cell culture and in vitro isolated protein experiments, activation of AMPK stimulates nitric oxide (NO) production via phosphorylation of endothelial nitric oxide synthase (eNOS), 2) stimuli associated with AMPK activation relax isolated vascular smooth muscle preparations from healthy animals, and 3) acute activation of AMPK in vivo induces hypotension in normotensive animals, an effect that could be indicative of reduced vascular tone. Together these findings prompt the logical hypothesis that acute activation of AMPK induces relaxation that is both endothelium-, NO-dependent and also vascular smooth muscle dependent; however the direct effects of AMPK activation on the regulation of vascular tone in the context of intact healthy arteries in vitro or in situ have not been tested. AMPK activation is dysregulated in essential hypertension and aging, conditions both characterized by vasomotor dysfunction. The integrity of AMPK-mediated vasomotor effects has not been evaluated in any model of vascular dysfunction or in the presence of AMPK dysregulation, and so it is unknown if or to what extent, activation of AMPK alters vascular tone in vessels with these impairments. The mechanisms of AMPK-mediated vasomotor effects have also not been delineating in healthy or dysfunctional arteries. Studying basic vascular signalling mechanisms in both healthy and dysfunctional models is important for understanding physiological function and regulation of vascular tissue, as well as to understand vascular pathology and aid in the development of therapeutic interventions. Collectively these considerations present compelling reasons to investigate the role of AMPK in vasomotor function in health and disease. The unifying purpose of this thesis was therefore to investigate the role of AMP-activated protein kinase in regulating vascular tone in arteries of healthy, hypertensive and aged rats. Experimental Approach and Main Findings: The global objective of the thesis is satisfied by four main studies that utilize a combination of in vitro isolated artery preparations to assess vasomotor function, biochemical analyses and in vivo hemodynamic assessments. In Study 1, we characterize the basic nature of the vasomotor response generated acutely by the pharmacological AMPK activator AICAR in vitro in isolated aorta of normotensive (Wistar-Kyoto rats; WKY) and hypertensive rats (Spontaneously Hypertensive rats; SHR), and the mechanisms mediating these responses. In these experiments, acute activation of AMPK using AICAR induced dose-dependent relaxation of isolated, precontracted arteries from WKY and SHR that was dependent in part on both the endothelium and vascular smooth muscle, and vasorelaxation to AICAR was enhanced in aortic rings of SHR versus those of WKY. In WKY, the endothelium-dependent component of relaxation to AICAR was solely NO-mediated, while in SHR it was dependent on both elevated NO-bioactivity and blunted COX-dependent contraction. In Study 2, we investigate the mechanisms responsible for AMPK-mediated inhibition of endothelium- and cyclooxygenase-dependent vasocontraction in aorta from WKY and SHR (a response enhanced in arteries of hypertensive rats that contributes to vasomotor dysfunction). Pre-activation of AMPK blunted endothelium-dependent contractions to acetylcholine in isolated, non-precontracted WKY and SHR aortic rings. The mechanisms accounting for this effect of AICAR were endothelium-specific, occurring via inhibition of the ACh-stimulated production/release of 6-keto-prostaglandin F1α, the major product of prostacyclin, which is the key prostanoid responsible for endothelium-dependent contractions in aorta of WKY and SHR. AMPK activation had no effect on vascular smooth muscle responsiveness to TP-receptor agonists, ruling out a contribution of vascular smooth muscle mechanisms. In Study 3, we examine responses and mechanisms associated with acute pharmacological AMPK activation on vascular tone of isolated mesenteric resistance arteries in vitro, and on in vivo hemodynamics in WKY and SHR. These experiments revealed that administration of AICAR acutely in vivo acutely reduced blood pressure by ~70mmHg in SHR and this effect was partly NO-dependent. In contrast, AICAR had no effect on blood pressure in WKY. Activation of AMPK also produced vasodilation of isolated, precontracted WKY and SHR resistance mesenteric arteries in vitro, and this was dependent on NO to a greater extent in SHR than in WKY. Together, the parallel reductions in blood pressure in vivo and relaxation of isolated arteries in vitro support reduced vascular resistance as a potential explanation for the in vivo blood pressure effects. Finally, Study 4 characterizes the basic vasodilatory responses to acute AMPK activation and mechanisms associated with these responses in aorta from aged animals and their young counterparts (male Sprague Dawley rats) to glean insight using an additional model of vasomotor dysfunction. In this study, acute activation of AMPK using AICAR generates relaxation in a dose-dependent manner that is partly endothelium-, NO-dependent and partly reliant on vascular smooth muscle in precontracted aorta of both young and aged rats. Similar to the findings of Study 1 in SHR versus WKY, vasodilatory response to AICAR were also enhanced in dysfunctional aorta of aged rats versus healthy aorta of young animals. Other agents shown to activate AMPK in other tissues and models, the anti-diabetic drug metformin and the polyphenol resveratrol, generated varying amounts of relaxation in vascular smooth muscle of young and aged aortic rings. These effects were only associated with AMPK activation in rings treated with metformin but not resveratrol. Conclusions and Perspectives: These findings are the first to characterize the vasomotor responses generated by acutely activating AMPK in intact arteries of any hypertensive or aging model, and to delineate mechanisms mediating these responses in healthy and dysfunctional vessels. Despite vasomotor dysfunction and dysregulated AMPK activity in arteries of hypertensive and aged rats, acute AMPK activation still generates robust relaxation responses via endothelium- and NO-dependent relaxation, inhibition of enhanced endothelium-dependent contractions in SHR, and direct relaxation of the vascular smooth muscle; effects that would aid in reversing the dysfunctional characteristics of arteries from these animals, and may recommend AMPK as a useful therapeutic target for interventions aimed at improving vasomotor function. Future studies will be necessary to reveal whether AMPK plays a role in generating acute changes in vessel tone induced by AMPK-activating physiological stimuli in situ (i.e. such as shear stress during exercise). Together these data continue to support AMPK as a novel regulator of vascular tone, yield valuable, novel, mechanistic insight into AMPK-mediated regulation of vasomotor function in arteries during health, disease and aging, and highlight the need for continued investigation into a vasoregulatory function for AMPK in health and disease.
Addressing Cultural Vulnerabilities in Arctic Tourism: Kindness as 'Third Space'
(University of Waterloo, 2016-09-20) Leeming, Julie
The changing climate and its impending impacts on Northern regions has ultimately initiated increased interest in Arctic tourism, providing tourists with a rationale for travel to these regions before they deteriorate further, or completely vanish (Lemelin et al., 2010; Hall & Saarinen, 2010). Previous research examining impacts of tourism in Arctic regions denotes that when tourism is introduced into rural and sparsely populated arctic regions, local communities may become overwhelmed by the influx of visitors, causing various forms of social tension, and more prominent feelings of invasion and vulnerability (Fay & Karlsdottir, 2011; Kajan, 2014). While there is evidence that tourism can easily foster impersonal and hostile relationships between tourists and host populations, it is imperative to also recognize that trust and understanding between cultures in tourism can exist in situations or encounters where tourists and hosts can move beyond the prescriptions or constructions that solidify cultural difference, and beyond “the constraints of a dominant hegemonic culture,” into what is termed the third space – a space that creates an intercultural context for symbolic interaction (Wearing & Wearing, 2006, p. 153). Using tourism in Iceland as a context, this thesis seeks to define and discuss the third space framework through the narratives of Icelandic hosts and visiting tourists, and their positive encounters of kindness and responsibility. Results of this ethnographic inquiry revealed that such encounters do have the potential to bridge initial feelings of cultural difference and vulnerability, ultimately creating a space of mutual understanding and cultural learning between the host and tourist, and enabling increased resiliency among the host population. This study also revealed specific social/cultural, spatial/environmental, and temporal circumstances enabling kindness to function in a tourism context.
Addressing Health Care Needs For Frail Seniors In Canada: The Role of InterRAI Instruments
(Canadian Geriatrics Society, 2013-12-30) Heckman, George A.; Gray, Leonard C.; Hirdes, John P.
Fiscal pressure on the Canadian health care system results from rising numbers of frail seniors with multiple concurrent medical co-morbidities and geriatric syndromes. Improving outcomes in such seniors is contingent on a comprehensive geriatric assessment (CGA) to identify strengths and deficits and to facilitate the development of a comprehensive care plan. InterRAI instruments are standardized, reliable, and validated suites of tools to conduct CGAs; they offer several benefits, including helping clinicians identify important health issues among patients, develop appropriate care plans, and monitor patient progess. These instruments also provide several benefits beyond the bedside, including quality indicators to assess care quality, and case-mix classification algorithms to facilitate funding of health services. Finally, interRAI instruments, which are implemented in several health care settings across Canada and abroad, provide a standardized and common language that is compatible with electronic medical records and will facilitate greater integration of the health care system.
Adolescent Identity Development: The Relationship with Leisure Lifestyle and Motivation
(University of Waterloo, 2007-09-11T20:33:06Z) Campbell, Jennifer
Identity development is a crucial process which occurs during the period of adolescence (Erikson, 1950, 1968). Researchers have suggested that the adolescent period is becoming prolonged due to increasing numbers of individuals pursuing post-secondary education (Kerckhoff, 2002; Larson, 2002; Mortimer & Larson, 2002). During this period known as “post-adolescence”, further identity formation is believed to take place (Mortimer & Larson, 2002). Despite these suggestions, little research has been performed regarding identity development during post-adolescence. In addition, the role of leisure during the identity formation period has largely been overlooked. The few studies that have been conducted on this topic focus on the relationship between leisure participation and identity development, while failing to acknowledge the role of other salient leisure lifestyle variables such as leisure experience, motivation and meaningfulness. In addition, previous studies have used global measures of identity, rather than considering separate dimensions of personal and social identity. The present study expands upon previous literature by investigating personal and social identity development during post-adolescence, and the relationship between identity and a variety of leisure lifestyle variables. Participants included 465 students from the University of Waterloo. Questionnaires were completed regarding leisure participation, meaningfulness derived from participation, leisure experience, motivation and identity. Results of the study indicate that identity development is still occurring during the period of post-adolescence. Leisure participation, meaningfulness, leisure experience and motivation all displayed some degree of a relationship with identity. Personal and social identities yielded differing associations with these leisure lifestyle factors. Personal identity was most strongly related to leisure experience, while social identity was associated with leisure motivation. Although causality cannot be inferred from the results of this study, indications do exist that these leisure lifestyle variables may exert some influence on the identity development process.
Adolescent Maternal Nutrition and Health in Uganda: Voices from the Community
(University of Waterloo, 2018-01-23) Nabugoomu, Josephine
INTRODUCTION: Over one quarter of adolescent girls in rural Uganda and more than one fifth of them in the Busoga region of Eastern Uganda experience pregnancy and childbirth. These young mothers have disproportionately high rates of poverty, food insecurity, social isolation and poor health, and lack adequate access to health care and employment. Improvement of adolescent maternal/child nutrition and health may be compromised by a number of barriers faced by young mothers. Challenges met by stakeholders who could support adolescent maternal/child health may also complicate issues. Community-level action is a key strategy to reverse the cycle of oppression for these girls and their offspring. There is scanty literature about studies that have focused on needs and barriers of teenage mothers, opportunities available in the community, challenges faced by service providers, and stakeholder recommendations and avenues of capacity building in rural Eastern Uganda with a goal of understanding influences on adolescent maternal/child nutrition and health. Moreover, the application of the social cognitive theory and ideas borrowed from the social ecological framework to this issue helps to emphasize the individual and environmental (social/economic/physical/nutrition/health service) factors that interact to influence the behaviors of young mothers. Since an aim of the research is ultimately to guide community-level intervention, it was important to understand context from the perspectives of a range of stakeholders of adolescent maternal/child nutrition and health relevant to the geographic setting of rural Jinja district. This study could help to inform further research and may help in forming feasible and acceptable community-based interventions towards enhancing adolescent maternal/child nutrition and health. OBJECTIVES AND METHODS: This qualitative research examined, from the perspectives of a range of community-level stakeholders, the needs, barriers, opportunities, challenges, recommendations and areas of capacity building for improved adolescent maternal/child nutrition and health. The research was conducted in the rural Budondo sub-county of Jinja district, Uganda. Based on constructs of the social cognitive theory (SCT), in depth individual interviews were conducted among 101 purposively sampled respondents recruited from parishes surrounding 6 public health centers of the study area. The study participants included: pregnant adolescent mothers (n=11); lactating young mothers with infants of 0-6 months (n=8); lactating mothers of infant 7-12 months (n=6); mothers of young mothers (n=6) and grandmothers of young mothers (n=5). Other interviewees were: midwives (n=7); traditional birth attendants (n=3); village health team members (n=5); doctors (n=4); teachers (n=5); head teachers (n=11); agriculture officers (n=3); religious leaders (n=3); village political leaders (n=6); staff members of non-governmental organizations in the study area (n=5); and sub-county and district area administrators (n=13). Interview recordings were transcribed word for word and then translated into English. Codes were created from the transcribed interviews based on the constructs of the SCT model (individual factors; environmental factors [including social, economic, physical, nutritional and health service environments] and, as relevant, behavioral factors) and a priori themes of the study objectives. Using Atlas-ti 7.5.4 phrases in each transcript were linked to the created codes which were networked towards the main theme of adolescent maternal/child nutrition and health. RESULTS: Needs reported by the study include schooling and home-based employment at the individual level; belonging and encouragement at the social level; jobs and money to purchase basic needs at the economic level; and shelter, beddings and clothing at the physical level. Other needs included: food for young mothers and their infants at the nutrition level; and medical supplies, health home visits and training in good newborn care practices at the health service level. Barriers identified were: young mothers’ lack of knowledge in income generation and food preparation skills and confidence to handle new responsibilities or stay in school at the individual level; harsh treatment and stigmatization by family members and medical staff at the social level: and, at the economic level: young mothers’ lack of experience in income generation, lack of academic job qualifications and/or capital/fees for self-employment, heavy responsibilities of motherhood, lack of markets, and government programs such as the National Agricultural Advisory Services (NAADS) which support adults and men with agricultural items, like seeds for planting or animals for rearing, but not girls. At the physical level, barriers included long distances and slippery roads to the health centers or training programs, failure to inherit land by girls (unlike boy children), and restriction from sharing houses with their parents as, culturally, young mothers are taken to become in-laws belonging to the families of the boys/men they had sex with. At the nutrition level: infants did not benefit from exclusive breastfeeding (EBF) due to a range of maternal factors including, in some cases, negative attitudes towards breastfeeding, insufficient breastmilk, return to school, or breastfeeding problems; and at health service level barriers included: late reporting of medical personnel, long waiting lines, absence of medicines, failure to receive delivery materials, absence of tailored medical attention, and poor health communications. Opportunities identified at the individual level were the positive attitudes of some young mothers towards: taking-up health advice and practices, laboring for a pay and keeping their pregnancies to term. At the social level, some parents and community members were kind and caring, and provided emotional support. At the economic level: some family and community support in transferring income generation skills to young mothers was identified. Similarly, at the physical level: provision of land and shelter by family and community members was sometimes reported. At the nutrition level: provision of food by families, and training and support in maternal/child feeding were assets. At the health service level, medical care and availability of health-related staff were reported for some health centers. These cases could be held up as examples. Challenges raised by stakeholders that could block the identified opportunities included: at the individual (stakeholder) level: demotivation due to serving with a low/no pay and negative attitudes of community members, and inadequate training in adolescent maternal care; at the social level: lack of an organization supporting young mothers; and at economic level: uncertainty regarding how to use available resources to better serve young mothers and how to enhance the quality of agriculture and handcrafted products to be competitive for desired market prices. At the physical level, challenges included use of the available land by families to better their own lives rather than their daughter’s, finding ways to provide for more proximal services, e.g., equipping village health team members (VHTs) with protective materials for their work. At the nutrition level, challenges included determining how to improve the skills in food preparation for mothers when faced with a lack of food and trained facilitators, and at health service level, meeting medical needs with poor access to medical supplies, poor working conditions and understaffing. Recommendations given by stakeholders included: individual level: sensitization of family and community members to support young mothers, and motivation of community members with pay; social level: community collective responsibility and policing for better health services, special schooling for young mothers, supervision of medical staff, presidential directive to fathers of babies who fail to assume financial responsibility, and use of suggestion boxes at health centers. At the economic level: employment creation, improved facilitation in agriculture, payment of service providers, putting up vocational institutes, and prioritizing the health sector within the national budget were recommended. At the physical level: building medical staff houses and operating theatres, provision of medical equipment, and supporting local health-related personnel with protective gear and delivery materials, were suggested. Further recommendations included, at the nutrition level, use of tailored nutrition education videos and expanding food preparation facilities, while at the health service level: adequate, timely and informed supply of medicines and medical supplies, employing more medical staff, having a designated space or health center for young mothers, and use of tailored health education videos. Capacity building avenues that were suggested included: at the individual level: training health personnel to meet the needs of young mothers, training young mothers and VHTs in income generation skills and use of adult VHTS by future organizations that could support young mothers; at the social level: training teachers and community workers to counsel parents; and at the economic level: teacher training to, in turn, train youth on handcraft skills while VHTs could train and monitor projects of young mothers. Other areas of capacity building included: at the physical level: training of local health-related personnel on use of anthropometry equipment to support better monitoring of maternal and child growth; at the nutrition level: training community workers in nutrition and food preparation to better support their training of mothers, and at the health service level: training of community workers, like VHTs, in the unique maternal/child health needs of adolescents and monitoring, and licensing traditional birth attendants (whose could be revised by the World Health Organization). DISCUSSION: The study revealed perceptions of diverse stakeholders that call for improved well-being of adolescent mothers and their infants at the individual and environment level in rural Uganda. By understanding the needs, barriers and supports of young mothers, challenges of service providers and suggested solutions, it may be possible to consider opportunities to shift behavior or overcome obstacles. Lessons from strategies used by a number of organizations in the study area or other districts in rural Uganda could be taken up for improved adolescent maternal/child nutrition and health. At the individual level, counselling, sensitization, and peer groups could be used to encourage, support and strengthen positive attitudes and practices of young mothers. For example, since young mothers were involved in family agriculture and home-based employment, personal projects in the same could be possible, while, staying in school could also be possible for mothers who were interested in schooling. At the social level, information sharing, counselling and sensitizing families, local community members, district administrators, civil society organizations and policy makers, could shift collective support for young mothers at home, schools, and health centers, as demonstrated elsewhere [Leerlooijer et al., 2014]. At the economic level, partnering with non-governmental organizations and government programs in the area could help in providing skill training, and grants, in the form of money or resources, to support income generation by young mothers. The said programs could also support train-the trainer opportunities for educators and other community workers. Use of agriculture for income generation is an ideal opportunity in the region as young mothers are involved in agriculture, since, on the gender level, women and girls are the major agriculture labor force in Africa. At the physical level, lessons learned from other studies could help to improve the well-being of young mothers through avenues such as family joint land ownership or and lobbying for infrastructure improvement and support to service providers such as medical staff, VHTs, and TBAs. At the nutritional level, production of food through crop growing and bird/animal rearing, in addition to adolescent maternal child nutrition education is important as suggested by several studies [Nabugoomu et al., 2015a; Nabugoomu et al., 2015b; Nabugoomu & Hanning, 2015; Shefner-Rogers 2014, Berti et al’, 2010]. Nutrition education by VHTs who are the community-based workers could also be explored as an opportunity suggested by other studies [Stanback et al., 2007; Tylleskär et al., 2011; Kirkwood et al., 2013; Penfold et al., 2014; Flax et al., 2014]. This opportunity would be possible as some of the VHTs were willing to use their homes for training of young mothers in practical food preparation skills. At the health service level, district and national authorities could be lobbied, so as to aid in the training of medical staff in adolescent friendly services, and taking and recording of measurements of young mothers and translating these measurements in a manner that can be understood by the young mothers. Lobbying to facilitate home visits by health-related personnel could also be helpful. Training of VHTs and TBAs in maternal/child health education and health monitoring by organizations such as World Vision [Ononge et al., 2016] could also help since VHTs and TBAs were trusted by community members. For example, these service providers could be used as agents of change for gender and cultural biases. This study involved a large, diverse sample of participants and hence captured a broad range of views. Conducting interviews in homes or places of work helped to make use of observations and extra information from non-participants for triangulation of information. In addition, observations at health centers were triangulated with views of stakeholders. CONCLUSION: Using the SCT, this study identified a range of needs and barriers faced by adolescent mothers in rural Uganda making them vulnerable to poor maternal/child health. Participants also identified opportunities that could support young mothers, challenges of service providers, and gave feasible steps to addressing the needs, barriers and challenges by building on available opportunities to enhance health and well-being. This research underpins the importance of research at the community level and the inclusion of knowledge users and decision makers in the process. Findings of this study may help to direct future community-based interventions for improvement of adolescent maternal/child nutrition and health.
Adult Hippocampal Neurogenesis, Cognitive Flexibility, and Depression
(University of Waterloo, 2016-02-23) Lui, Erika
Depression is a serious and complex mental health disorder that is becoming increasingly prevalent, and is among the leading causes of global disease burden. Although depression is thought to be primarily an affective disorder, there is growing evidence that it is associated with memory deficits. Adult hippocampal neurogenesis has been implicated in depression and may also contribute to cognitive flexibility. Therefore, the present study used an animal model of depression involving chronic corticosterone (CORT) injections to assess learning and memory, and changes in adult hippocampal neurogenesis. In Experiment I, rats were randomized to receive either CORT (40 mg/kg) or vehicle injections for 21 days. On the second day of treatment, all rats received injections of BrdU to label newborn neurons. Six days before the end of the CORT treatment, rats were subjected to behavioural testing in the Morris water maze (MWM). Neurogenesis was also assessed using immunofluorescence staining. Although CORT-treated rats performed on par with vehicle-treated rats during spatial learning of the MWM, cognitive flexibility of the CORT-treated rats was significantly impaired during the first day of reversal training. The probe test revealed enhanced memory retention of the platform location for the CORT-treated rats. Experiment II was similar to Experiment I in all respects, except that injections were stopped 3 days before behavioural assessment. In Experiment II, CORT-treated rats performed better in the spatial learning phase of the MWM, while reversal learning and memory retention in the probe test were no different than control animals. In both Experiment I and II, no difference in the number of newborn neurons between the two groups was observed. These findings suggest that cognitive flexibility is impaired in a CORT-induced animal model of depression, the effect is reversible and seems to be independent of suppressed hippocampal neurogenesis.
Advancing methods to capture and analyze dietary patterns
(University of Waterloo, 2024-08-12) Hutchinson, Joy
Background: Suboptimal diet quality is linked to poor health outcomes and is associated with many sociodemographic characteristics, including several that are indicators of inequities. Assessments of dietary intake have shifted over time from investigations of single foods and nutrients towards dietary patterns. This change has led to developments in methods to capture and analyze dietary patterns, from short tools that quickly assess the overall diet to novel analytic methods. These methodological advances present opportunities to better understand dietary patterns in Canada and globally. Research objectives: The objectives of this research were to (1) develop a brief dietary screener to assess alignment of dietary intakes with the 2019 Canada’s Food Guide healthy food choices recommendations; (2) develop a scoring system for the screener and assess the construct validity of the screener; (3) identify novel methods used to characterize dietary patterns through a scoping review of the literature; and (4) explore the capacity of probabilistic graphical models to expand our understanding of the joint relationships between multidimensional dietary patterns and intersecting sociodemographic characteristics. Methods and results: The first study in this dissertation (Chapter 4) discusses the process to develop the Canadian Food Intake Screener. This was achieved by mapping the dietary guidance in the 2019 Canada’s Food Guide and reviewing existing tools to develop a draft screener, which was reviewed by Health Canada and external collaborators (n=15). The screener was revised iteratively based on feedback from cognitive testing conducted among adults aged 18-65 years in English (n=17) and French (n=16) and from face and content validity testing conducted with experts (n=16). The screener was well understood overall and testing informed refinement to finalize the Canadian Food Intake Screener, which includes 16 questions to rapidly assess alignment of adults’ intake with the 2019 Canada’s Food Guide healthy food choices recommendations. The second study in the dissertation (Chapter 5) was conducted to develop a scoring system for the screener and evaluate the screener’s construct validity among adults aged 18 to 65 years. Analysis of variance (ANOVA) was used to compare screener scores among subgroups with known differences in diet quality. The correlation between scores on the screener and the Healthy Eating Food Index-2019 (HEFI-2019), which also assesses alignment of intake with the 2019 Canada’s Food Guide healthy food choices recommendations, was assessed. Adults aged 18-65 years (n=154) completed the screener, answered a range of questions about their health and sociodemographic characteristics, and completed up to two 24-hour dietary recalls. The mean screener score was 35 points (SD = 4.7; maximum 65), ranging from 25 (1st percentile) to 45 (99th percentile). Meaningful differences in screener scores were observed in hypothesized directions by gender identity (p = 0.06), perceived income adequacy (p = 0.07), education (p = 0.02), and smoking status (p = 0.003). The correlation between screener and HEFI-2019 scores was 0.53 (SE = 0.12). The screener demonstrated moderate construct validity, indicating that it is appropriate for use for rapid assessment of alignment of adults’ intake with the healthy food choices recommendations when comprehensive dietary assessment is not possible. In Chapter 6, novel methods used to characterize dietary patterns in peer-reviewed literature were summarized using a scoping review. The databases MEDLINE, CINAHL, and Scopus were searched using keywords such as such as machine learning, latent class analysis, and least absolute shrinkage and selection operator (LASSO) to identify novel methods used to describe dietary patterns. Of 5274 records identified, 24 met the inclusion criteria. Twelve of 24 articles were published since 2020. A range of methods was applied to identify dietary patterns, with nine studies using approaches that have applications in machine learning to characterize dietary patterns, and the remaining 15 using other novel methods such as latent class analysis, LASSO, or treelet transform. Future work to guide the application, interpretation, and comparability of these methods is necessary to enable synthesis of the literature to inform policies and programs. The final study (Chapter 7) in this dissertation examined the ability of probabilistic graphical models to explore the joint relationships between dietary patterns and sociodemographic characteristics. While prior research has established relationships between dietary patterns and sociodemographic characteristics, it has rarely considered the multidimensional relationships between dietary components or possible intersecting relationships among sociodemographic characteristics. Mixed graphical models, a network method, enable explorations of these complex joint relationships, which have largely been unexplored in the Canadian context. We conducted a secondary analysis of first 24-hour dietary recalls collected from adults aged 18 years and above who participated in the 2015 Canadian Community Health Survey Nutrition (n=14 097). Mixed graphical models were used to identify joint relationships between amounts consumed in grams of thirty log-transformed food groups and age, sex, education, income, household food security status, geographic region, employment status, and smoking status. Sociodemographic characteristics formed a network, with several pairwise relationships. Several dietary components also formed networks, often patterning by food group. Age and sex were the sociodemographic characteristics most strongly connected to dietary components. This research applied mixed graphical models to provide deeper insights into the internal structures of the dietary patterns of adults in Canada, and how sociodemographic characteristics are jointly related with dietary patterns. Probabilistic graphical models offer promise to complement existing methods to characterize dietary patterns, such as indices. Conclusions: This dissertation makes contributions to dietary patterns research with respect to both collecting data reflective of overall dietary patterns and analytic methods to capture their complexity. The advances from these studies can be applied to inform targeted research and policies promoting public health nutrition in Canada and beyond.

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