299 research outputs found
Establishing baseline travel patterns from smart-phone and spatial data
Investment in public transit infrastructure and services is essential to providing effective transportation alternatives, and it is important to monitor the progress of key performance indicators (KPIs) to ensure goals of major transit projects are being achieved. These key performance indicators provide replicable measurements related to different aspects of transportation and mobility. Through this thesis, data were collected and analyzed in relation to a set of key performance indicators in the context of Downtown Kitchener in the Region of Waterloo with the implementation of the ION Light Rail system to assess the current state of Downtown Kitchener, and its progression toward goals outlined in the Region of Waterloo’s Community Building Strategy and the Kitchener Planning Around Rapid Transit Stations plan. Data related to transit ridership, modal splits, and active transportation networks were summarized from a collection of datasets to establish a baseline of data prior to the introduction of light rail. This thesis investigated the process to collect and analyze these types of data through smart-phone GPS data collection during February and March of 2017 and Python scripts, alongside demographic surveys and other datasets for Downtown Kitchener.
Overall, a sample of baseline indicators have been gathered and assessed for Downtown Kitchener that demonstrated a high propensity for transit and active transportation usage, supported by public policy, with some exceptions or areas of improvement. The process taken in this thesis may be applied to additional areas throughout the Region of Waterloo prior to and following commencement of ION Light Rail operation
Future Elementary School Teachers' Conceptual Change Concerning Photosynthesis
The purpose of this study was to examine conceptual change among future elementary school teachers while studying a scientific text concerning photosynthesis. Students' learning goals in relation to their learning outcomes were also examined. The participants were future elementary school teachers. The design consisted of pre- and post-tests. The study revealed that student teachers have severe misconceptions concerning photosynthesis. However, the results indicated that a coherent expository text works as an effective support in the learning process. Further, results showed that students who express high-level learning goals are more likely to undergo conceptual change than students with low-level learning goals. The study highlights the importance of science education in teacher training at universities.</p
Genetic variation in the hTAS2R38 taste receptor and food consumption among Finnish adults
Genetic variation in bitter taste receptors, such as hTAS2R38, may affect food preferences and intake. The aim of the present study was to investigate the association between bitter taste receptor haplotypes and the consumption of vegetables, fruits, berries and sweet foods among an adult Finnish population. A cross-sectional design utilizing data from the Cardiovascular Risk in Young Finns cohort from 2007, which consisted of 1,903 men and women who were 30-45 years of age from five different regions in Finland, was employed. DNA was extracted from blood samples, and hTAS2R38 polymorphisms were determined based on three SNPs (rs713598, rs1726866 and rs10246939). Food consumption was assessed with a validated food frequency questionnaire. The prevalence of the bitter taste-sensitive (PAV/PAV) haplotype was 11.3 % and that of the insensitive (AVI/AVI) haplotype was 39.5 % among this Finnish population. PAV homozygotic women consumed fewer vegetables than did the AVI homozygotic women, 269 g/day (SD 131) versus 301 g/day (SD 187), respectively, p = 0.03 (multivariate ANOVA). Furthermore, the intake of sweet foods was higher among the PAV homozygotes of both genders. Fruit and berry consumption did not differ significantly between the haplotypes in either gender. Individuals perceive foods differently, and this may influence their patterns of food consumption. This study showed that the hTAS2R38 taste receptor gene variation was associated with vegetable and sweet food consumption among adults in a Finnish population.Peer reviewe
Cationic polymers for DNA origami coating - examining their binding efficiency and tuning the enzymatic reaction rates
DNA origamis are fully tailored, programmable, biocompatible and readily functionalizable nanostructures that provide an excellent foundation for the development of sophisticated drug-delivery systems. However, the DNA origami objects suffer from certain drawbacks such as low cell-transfection rates and low stability. A great deal of studies on polymer-based transfection agents, mainly focusing on polyplex formation and toxicity, exists. In this study, the electrostatic binding between a brick-like DNA origami and cationic block-copolymers was explored. The effect of the polymer structure on the binding was investigated and the toxicity of the polymer-origami complexes evaluated. The study shows that all of the analyzed polymers had a suitable binding efficiency irrespective of the block structure. It was also observed that the toxicity of polymer-origami complexes was insignificant at the biologically relevant concentration levels. Besides brick-like DNA origamis, tubular origami carriers equipped with enzymes were also coated with the polymers. By adjusting the amount of cationic polymers that cover the DNA structures, we showed that it is possible to control the enzyme kinetics of the complexes. This work gives a starting point for further development of biocompatible and effective polycation-based block copolymers that can be used in coating different DNA origami nanostructures for various bioapplications.Peer reviewe
Dietary patterns and their associations with home food availability among Finnish pre-school children : a cross-sectional study
Objective: To study the associations between home food availability and dietary patterns among pre-school children. Design: Cross-sectional study in which parents of the participating children filled in an FFQ and reported how often they had certain foods in their homes. We derived dietary pattern scores using principal component analysis, and composite scores describing the availability of fruits and vegetables as well as sugar-enriched foods in the home were created for each participant. We used multilevel models to investigate the associations between availability and dietary pattern scores. Setting: The DAGIS study, Finland. Subjects: The participants were 864 Finnish 3-6-year-old children recruited from sixty-six pre-schools. The analyses included 711 children with sufficient data. Results: We identified three dietary patterns explaining 16.7% of the variance. The patterns were named 'sweets-and-treats' (high loadings of e.g. sweet biscuits, chocolate, ice cream), 'health-conscious' (high loadings of e.g. nuts, natural yoghurt, berries) and 'vegetables-and-processed meats' (high loadings of e.g. vegetables, cold cuts, fruit). In multivariate models, the availability of fruits and vegetables was inversely associated with the sweets-and-treats pattern (beta = -0.05, P <0.01) and positively associated with the health-conscious (beta = 0.07, P <0.01) and vegetables-and-processed meats patterns (beta = 0.06, P <0.01). The availability of sugar-enriched foods was positively associated with the sweets-and-treats pattern (beta = 0.10, P <0.01) and inversely associated with the health-conscious pattern (beta = -0.03, P <0.01). Conclusions: Considering dietary patterns, the availability of sugar-enriched foods in the home seems to have a stronger role than that of fruits and vegetables. Parents should restrict the availability of unhealthy foods in the home.Peer reviewe
Investigation of human iPSC-derived cardiac myocyte functional maturation by single cell traction force microscopy
Recent advances have made it possible to readily derive cardiac myocytes from human induced pluripotent stem cells (hiPSC-CMs). HiPSC-CMs represent a valuable new experimental model for studying human cardiac muscle physiology and disease. Many laboratories have devoted substantial effort to examining the functional properties of isolated hiPSC-CMs, but to date, force production has not been adequately characterized. Here, we utilized traction force microscopy (TFM) with micro-patterning cell printing to investigate the maximum force production of isolated single hiPSC-CMs under varied culture and assay conditions. We examined the role of length of differentiation in culture and the effects of varied extracellular calcium concentration in the culture media on the maturation of hiPSC-CMs. Results show that hiPSC-CMs developing in culture for two weeks produced significantly less force than cells cultured from one to three months, with hiPSC-CMs cultured for three months resembling the cell morphology and function of neonatal rat ventricular myocytes in terms of size, dimensions, and force production. Furthermore, hiPSC-CMs cultured long term in conditions of physiologic calcium concentrations were larger and produced more force than hiPSC-CMs cultured in standard media with sub-physiological calcium. We also examined relationships between cell morphology, substrate stiffness and force production. Results showed a significant relationship between cell area and force. Implementing directed modifications of substrate stiffness, by varying stiffness from embryonic-like to adult myocardium-like, hiPSC-CMs produced maximal forces on substrates with a lower modulus and significantly less force when assayed on increasingly stiff adult myocardium-like substrates. Calculated strain energy measurements paralleled these findings. Collectively, these findings further establish single cell TFM as a valuable approach to illuminate the quantitative physiological maturation of force in hiPSC-CMs
Fungal Treatment Modifies Kraft Lignin for Lignin- and Cellulose-Based Carbon Fiber Precursors
The kraft lignin's low molecular weight and too high hydroxyl content hinder its application in bio-based carbon fibers. In this study, we were able to polymerize kraft lignin and reduce the amount of hydroxyl groups by incubating it with the white-rot fungus Obba rivulosa. Enzymatic radical oxidation reactions were hypothesized to induce condensation of lignin, which increased the amount of aromatic rings connected by carbon-carbon bonds. This modification is assumed to be beneficial when aiming for graphite materials such as carbon fibers. Furthermore, the ratio of remaining aliphatic hydroxyls to phenolic hydroxyls was increased, making the structure more favorable for carbon fiber production. When the modified lignin was mixed together with cellulose, the mixture could be spun into intact precursor fibers by using dry-jet wet spinning. The modified lignin leaked less to the spin bath compared with the unmodified lignin starting material, making the recycling of spin-bath solvents easier. The stronger incorporation of modified lignin in the precursor fibers was confirmed by composition analysis, thermogravimetry, and mechanical testing. This work shows how white-rot fungal treatment can be used to modify the structure of lignin to be more favorable for the production of bio-based fiber materials.Peer reviewe
Psychosocial environment in childhood and body mass index growth over 32 years
The psychosocial environment and especially various psychosocial risks in childhood have been shown to predict later negative health behavior and health problems. In this study, we examined whether various psychosocial factor domains in childhood and adolescence: socioeconomic status, theemotional family environment (parental nurturance, life-satisfaction), parental lifestyle, life-events, the child's self-regulatory behavior and the child's social adaptation were associated with body mass index (BMI) trajectories individually by domain and as a cumulative score across domains. The participants were a nationally representative sample of 2016 men and women fromthe Young Finns study aged 3-18 years at study entry in 1980. Their BMI wasmeasured at six study phases from 1980 to 2012. Their parents reported all the factors related to their psychosocial environment in 1980. The participants responded to questions on adulthood socioeconomic status in 2007. The accumulation of psychosocial factors in childhood was the main exposure variable. The findings fromrepeated measuresmultilevelmodeling showed that parental lifestyle and life-events and the more positive cumulative psychosocial factors score were associated with a slower increase in BMI during follow-up (regression coefficient range from - 0.06 to -0.50). In conclusion, the psychosocial environment in childhood and adolescence, particularly parental lifestyle and lack of stressful life-events, are associated with a lower increase of BMI. (C) 2017 Elsevier Inc. All rights reserved.Peer reviewe
Ideal cardiovascular health in childhood-Longitudinal associations with cardiac structure and function : The Special Turku Coronary Risk Factor Intervention Project (STRIP) and the Cardiovascular Risk in Young Finns Study (YFS)
Background: Ideal cardiovascular health (CVH), defined by the American Heart Association, is associated with incident cardiovascular disease in adults. However, association of the ideal CVH in childhood with current and future cardiac structure and function has not been studied. Methods and results: The sample comprised 827 children participating in the longitudinal Special Turku Coronary Risk Factor Intervention Project (STRIP) and The Cardiovascular Risk in Young Finns Study (YFS). In STRIP, complete data on the seven ideal CVH metrics and left ventricular (LV) mass measured with echocardiography were available at the age of 15 (n= 321), 17 (n= 309) and 19 (n= 283) years. In YFS, the cohort comprised children aged 12-18 years (n = 506) with complete ideal CVH metrics data from childhood and 25 years later in adulthood, and echocardiography performed in adulthood. In STRIP, ideal CVH score was inversely associated with LV mass during childhood (P = 0.036). In YFS, childhood ideal CVH score was inversely associated with LV mass, LV end-diastolic volume, E/e' ratio, and left atrium end-systolic volume in adulthood (all P <0.01). In addition, improvement of the ideal CVH score between childhood and adulthood was inversely associated with LV mass, LV end-diastolic volume, E/e' ratio, and left atrium end-systolic volume (all P Conclusions: Childhood ideal CVH score has a long-lasting effect on cardiac structure and function, and the association is evident already in childhood. Our findings support targeting the ideal CVHmetrics as part of primordial prevention of cardiovascular diseases. (C) 2016 Elsevier Ireland Ltd. All rights reserved.Peer reviewe
Aerosol properties associated with air masses arriving into the North East Atlantic during the 2008 Mace Head EUCAARI intensive observing period: an overview
As part of the EUCAARI Intensive Observing Period, a 4-week campaign to measure aerosol physical, chemical and optical properties, atmospheric structure, and cloud microphysics was conducted from mid-May to mid-June, 2008 at the Mace Head Atmospheric Research Station, located at the interface of Western Europe and the N. E. Atlantic and centered on the west Irish coastline. During the campaign, continental air masses comprising both young and aged continental plumes were encountered, along with polar, Arctic and tropical air masses. Polluted-continental aerosol concentrations were of the order of 3000 cm(-3), while background marine air aerosol concentrations were between 400-600 cm(-3). The highest marine air concentrations occurred in polar air masses in which a 15 nm nucleation mode, with concentration of 1100 cm(-3), was observed and attributed to open ocean particle formation. Continental air submicron chemical composition (excluding refractory sea salt) was dominated by organic matter, closely followed by sulphate mass. Although the concentrations and size distribution spectral shape were almost identical for the young and aged continental cases, hygroscopic growth factors (GF) and cloud condensation nuclei (CCN) to total condensation nuclei (CN) concentration ratios were significantly less in the younger pollution plume, indicating a more oxidized organic component to the aged continental plume. The difference in chemical composition and hygroscopic growth factor appear to result in a 40-50% impact on aerosol scattering coefficients and Aerosol Optical Depth, despite almost identical aerosol microphysical properties in both cases, with the higher values been recorded for the more aged case. For the CCN/CN ratio, the highest ratios were seen in the more age plume. In marine air, sulphate mass dominated the sub-micron component, followed by water soluble organic carbon, which, in turn, was dominated by methanesulphonic acid (MSA). Sulphate concentrations were highest in marine tropical air - even higher than in continental air. MSA was present at twice the concentrations of previously-reported concentrations at the same location and the same season. Both continental and marine air exhibited aerosol GFs significantly less than ammonium sulphate aerosol pointing to a significant organic contribution to all air mass aerosol properties
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