1,721,033 research outputs found
Preschool Diet and Child Health Outcomes: The CHILD Cohort Study
Full text linkObesity and asthma are on the rise and have origins in childhood, with overlapping risk factors. Asthma is one of the most common childhood diseases and one of the leading causes of pediatric hospitalization. Obesity and asthma can lead to increased risk for long-term health issues and resulting burden of cost to the healthcare system in Canada. These outcomes may be minimized by understanding important modifiable risk factors, such as diet in early life. This thesis aims to understand the association between dietary patterns and obesity and asthma in preschool-aged children, and the impact of sex on these outcomes, drawing data from the Canadian CHILD Cohort Study. The results of this thesis may spark further research directions, which may improve dietary recommendations for preschool aged children and improve long term health and disease prevention.M.Sc
Identifying the Impact of Early-Life Lower Respiratory Tract Infections on the Development of Preschool Asthma and Atopic Disease in the CHILD Study
Full text linkThis dissertation provides an exploration of the association between lower respiratory tract infections (LRTIs) in early life and the development of preschool asthma and atopic diseases in Canadian children, utilizing a large bio-informatics dataset from the CHILD Study. By analyzing lung function parameters, inflammatory serum biomarkers, antibiotic usage, and gut microbiome profiles, this dissertation outlines associations that contribute to our understanding of these complex diseases. Early-life LRTIs were found to correlate with low neonatal lung function and changes in ventilation inhomogeneity, as assessed by spirometry and the Multiple Breath Washout test. LRTIs were linked with modifications in serum proteins and immune responses, shedding light on potential pathways leading to asthma development. This dissertation also confirmed a substantial role of systemic antibiotic exposure in early life, particularly when prescribed for respiratory indications, on the risk of preschool asthma. A similar pattern was observed for the development of atopic dermatitis (AD), where antibiotic-induced shifts in microbial populations and metabolic functions suggest a link between gut microbiome perturbations and allergic diseases. We emphasize the critical period of the first year of life, where antibiotic administration had a dose-response relationship with an increased AD risk. Moreover, the dissertation outlines specific microbiome alterations—such as decline of beneficial short chain fatty acid producing bacteria like Bifidobacterium and Eubacterium spp. and changes in functional pathways—linked to both AD and antibiotic use. These findings suggest potential biomarkers for predicting and possibly preventing AD development. In summary, this research challenges traditional hypotheses of LRTI impact on asthma and atopic disease, instead suggesting that the relationship between LRTIs and these diseases involves dynamic interactions with the microbiome. This paradigm shift offers new avenues for prevention and treatment strategies and highlights the importance of careful systemic antibiotic use in early childhood and its impact on long-term health outcomes. Ph.D
Longitudinal Measures of Lung Function in Healthy Infants
Full text linkEffective treatment of paediatric pulmonary disease relies on early diagnostics, and thus requires pulmonary function testing. Before infant pulmonary function testing can be applied to detect disease, it must first be understood in health, especially in the context of the developing lung. Adult studies have suggested that the rapid expansion of alveoli leads to faster growth in the lung parenchyma with respect to the conducting airways. By longitudinally evaluating lung function parameters that approximate the size of the parenchyma and the airways in infants, it can be determined whether dysanapsis is present in this young age group. However, while we were unable to find functional dysanapsis in tidal breathing measures, it was found when comparing forced flow and volumetric measures. This indicates that while the airways are proportionally larger in youngest infants, rapid parenchymal expansion leads a decrease in the relative size of these airways compared to overall lung volume.M.Sc.2017-12-12 00:00:0
The Healthcare Burden of Pediatric Cough and its Association with Preschool Asthma
Full text linkAsthma is the most common chronic airway disease and contributes to pediatric healthcare burden. Although cough is a clinically relevant asthma symptom, predictive tools prioritize wheeze, leaving the burden of cough underexplored. This thesis examines associations between cough, asthma, and healthcare utilization, and identifies longitudinal cough trajectories in Canadian preschool-aged children using data from the CHILD Study, a prospective birth cohort. Parent-reported and clinical questionnaires captured cough presence, duration, severity, and frequency; wheeze; unscheduled doctor visits (UDVs); hospital visits (HVs); and medication use, including bronchodilators and corticosteroids (inhaled and oral). Generalized estimating equations assessed longitudinal associations, while group-based trajectory modeling identified cough patterns. Cough lasting ≥4 days or of moderate-severe intensity was associated with increased medication use and healthcare visits. Three distinct cough trajectories were identified, where the late-onset trajectory was associated with UDVs and bronchodilator use. These findings suggest that cough warrants careful evaluation by clinicians in early childhood.M.Sc
Infant Nasal Microbiome and Respiratory Health Outcomes in Early Childhood in the CHILD Cohort
Full text linkThe microbes that reside on the surface of our nose and sinuses make up the nasal microbiome. Using the data from the CHILD Cohort Study, a large Canadian prospective longitudinal cohort, we sampled the nasal microbiome and examined which environmental factors were associated with nasal microbiome alpha diversity and differential abundance, the effects ofviral presence on the nasal microbiome and if the nasal microbiome was associated with early life respiratory disease (asthma, wheeze, and allergic rhinitis). The infant nasal microbiome was associated with many environmental factors including prenatal smoke exposure and older siblings.Infants with viral presence had decreased alpha diversity and increased Moraxella sp.8 and Haemophilus sp.41. Additionally, the change in alpha diversity and individual operationaltaxanomic units (OTUs) between 3 and 12 months was associated with when infants had viral presence. Finally, infants with high asthma risk, wheeze and allergic rhinitis had multiple differentially abundant OTUs in infancy.M.Sc
Lung Clearance Index as a Marker of Ventilation Inhomogeneity in Early Childhood with Health and Disease
No full textRationale: Ventilation inhomogeneity (VI) may be an early sign of obstructive airway disease. The lung clearance index (LCI) has been suggested as a sensitive marker of VI, although it has not been well characterized in young children in health and in those with CF and asthma.
Objective: To determine if LCI can detect VI in asymptomatic infants and preschool-age subjects with CF or wheeze/asthma compared to healthy controls.
Methods: Sulphur hexafluoride (SF6) multiple breath washout (MBW) testing was completed in all subjects.
Results: LCI was found to be dependent on age in a large healthy cohort. Accounting for age, LCI was significantly elevated in disease groups compared to healthy controls in early childhood, illustrating early presence of VI in wheezy infants and the progression of disease in CF. Furthermore, the effects of breathing pattern and the variability of MBW parameters showed positive associations with age and VI.MAS
Lung Clearance Index as a Marker of Ventilation Inhomogeneity in Early Childhood with Health and Disease
Full text linkRationale: Ventilation inhomogeneity (VI) may be an early sign of obstructive airway disease. The lung clearance index (LCI) has been suggested as a sensitive marker of VI, although it has not been well characterized in young children in health and in those with CF and asthma.
Objective: To determine if LCI can detect VI in asymptomatic infants and preschool-age subjects with CF or wheeze/asthma compared to healthy controls.
Methods: Sulphur hexafluoride (SF6) multiple breath washout (MBW) testing was completed in all subjects.
Results: LCI was found to be dependent on age in a large healthy cohort. Accounting for age, LCI was significantly elevated in disease groups compared to healthy controls in early childhood, illustrating early presence of VI in wheezy infants and the progression of disease in CF. Furthermore, the effects of breathing pattern and the variability of MBW parameters showed positive associations with age and VI.MAS
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
