The impact of new government childcare accreditation standards on children's in-care physical activity and sedentary time.

BACKGROUND: A new physical activity and sedentary behaviour accreditation standard criterion for childcare settings was introduced by the provincial government in Alberta, Canada. The primary objective of this study was to examine if changes for in-care physical activity and sedentary time (ST) differed between centres in and around Edmonton, Alberta after implementing the new accreditation standards and non-accredited control centres in and around Ottawa, Ontario. Secondary objectives were to examine whether baseline age group (toddler, preschooler) or the childcare environment moderated any group differences in change of the primary outcomes. Furthermore, accreditation and control group differences in change of children's body mass index (BMI) Z-scores or cognitive development as well as educators' perceptions of the primary outcomes were explored. METHODS: Participants were 252 toddlers (19-35 months) and preschoolers (36-60 months) in childcare centres from Alberta (n = 11) and Ontario (n = 8) in the supporting Healthy physical AcTive CHildcare setting (HATCH) study. In-care ST, light-intensity physical activity (LPA), and moderate- to vigorous-intensity physical activity (MVPA) were accelerometer-derived before and 6 months after the implementation of the new standards. At both time points, cognitive development (working memory, expressive vocabulary), heights, and weights were measured, and BMI Z-scores were calculated. Additionally, the childcare environment was observed using the Environment and Policy Assessment and Observation (EPAO) and Movement Environment Rating Scale (MOVERS) tools. Demographic characteristics were parent-reported and weather variables were derived from Environment Canada data. Mixed models were conducted. RESULTS: In adjusted models (n = 241), change in children's in-care ST (B = -0.07, 95%CI: - 1.43,1.29), LPA (B = 0.08, 95%CI: - 0.89,1.05), and log-transformed MVPA (B = 0.01, 95%CI: - 0.09,0.11) were not significantly different between accreditation and control groups. Age group and the childcare environment were not moderators. Significant increases in BMI Z-score (B = 0.19, 95%CI: 0.03,0.35) and high working memory (OR = 3.24, 95%CI: 1.32,7.97) were observed in the accreditation group and significant increases in expressive vocabulary (B = 3.18, 95%CI: 0.05,6.30) were observed in the control group. CONCLUSIONS: The new accreditation criterion may not significantly change physical activity or ST in childcare settings and therefore may not explain findings for BMI Z-scores and cognitive development. Additional training and resources may be needed.

Associations between screen time and cognitive development in preschoolers.

Objectives: To examine the cross-sectional associations between screen time and cognitive development in preschoolers. Methods: Participants were 97 preschoolers (36 to 60 months) in Alberta and Ontario, Canada in the supporting Healthy physical AcTive Childcare setting (HATCH) study. The time that children spent watching television, videos or DVDs (television time) or playing video or computer games (video game time) on a television, computer, or portable device was assessed using a parental questionnaire. Television time and video game time were summed to calculate total screen time. Adherence to the screen time recommendation (≤1 hour/day) of the Canadian 24-Hour Movement Guidelines was calculated. Expressive vocabulary and working memory were assessed using the Early Years Toolbox. Due to the distribution of working memory, it was categorized as a binary variable based on the median score. The associations between screen time and cognitive development were examined using mixed models (expressive vocabulary) or generalized mixed models (working memory). Results: Screen time was not associated with expressive vocabulary. Preschoolers who had higher total screen time were less likely to have better working memory (OR=0.52; 95%CI:0.31, 0.88), despite the null associations for television time (P=0.155) and video game time (P=0.079). Preschoolers who met the screen time recommendation were more likely to have higher working memory capacity (OR=3.48; 95%CI:1.06, 11.47), compared to those who did not meet the recommendation. Conclusion: Limiting total screen time to no more than one hour per day may facilitate working memory development in preschoolers. Screen time may be unrelated to expressive language development in this age group.

Longitudinal correlates of sleep duration in young children.

OBJECTIVE: The primary aim of this study was to longitudinally examine potential demographic and screen time correlates of nap duration, nighttime sleep duration, and total sleep duration in young children over two time points. METHODS: Data from the supporting Healthy physical AcTive Childcare setting (HATCH) study were analyzed. Participants were 206 toddlers (19-35 months) and preschoolers (36-60 months) in Alberta and Ontario, Canada. Child age, screen time (television, video games), and sleep duration (nap, nighttime) were measured at baseline and six-month follow-up, while other demographic variables were assessed at baseline only using the HATCH parental questionnaire. Mixed models were performed to examine the associations between potential correlates and sleep duration over time. RESULTS: In the multiple regression models, significant correlates of total sleep duration (min/d) were child age (months; B = -3.03; 95%CI:-3.88,-2.19) and parental education (bachelor's degree vs. below bachelor level; B = 29.74, 95%CI:7.43,52.06). Significant correlates of nighttime sleep duration (min/d) included child age (B = -0.81; 95CI%:-1.53,-0.10), child race/ethnicity (Caucasian vs. non-Caucasian; B = 15.31; 95%CI:0.38,30.25), household income (>$150,000 vs. <$50,000; B = 32.93, 95%CI:9.80,56.06), television time (B = -0.19, 95%CI:-0.32,-0.05), video games time (B = -0.19, 95%CI: -0.38, -0.01) and total screen time (B = -0.19; 95%CI:-0.29,-0.08). Significant correlates of nap duration (min/d) were child age (B = -2.10; 95%CI:-2.68,-1.51) and race/ethnicity (Caucasian vs. non-Caucasian; B = -13.73; 95%CI:-25.78,-1.68). CONCLUSION: Young children who were non-Caucasian, from lower income families, who had less-educated parents, or who had more screen time tended to have shorter sleep duration. Targeting these demographic groups and screen time appears important for promoting adequate sleep duration in early childhood.

Associations between sleep duration, adiposity indicators, and cognitive development in young children.

OBJECTIVE: This study aimed to examine the associations between sleep duration, adiposity indicators, and cognitive development in young children. METHODS: Participants were 217 children aged 19-60 months in Canada in the supporting Healthy physical AcTive Childcare setting (HATCH) study. Nap duration and nighttime sleep duration were assessed using a parent questionnaire and were summed up as total sleep duration. Body mass index (BMI) z-scores and weight status were determined using the World Health Organization growth standards. Expressive vocabulary and working memory were assessed using the Early Years Toolbox in preschoolers only (36-60 months; n = 101). Mixed models (BMI z-score, expressive vocabulary) and generalized mixed models (weight status, working memory) were conducted. RESULTS: A linear association between total sleep duration and BMI z-score (B = -0.12; 95% CI: -0.23, -0.01) were observed. Compared to children having nighttime sleep within ±1SD (9.13-11.13 h/d) of the mean, those having shorter nighttime sleep had higher BMI z-scores (B = 0.39; 95% CI: 0.06, 0.73) and an increased risk of being overweight (OR = 4.54; 95% CI: 1.39, 14.81). Nap duration was not associated with adiposity indicators. In preschoolers, sleep duration was not associated with expressive vocabulary. Total sleep duration and nap duration were not associated with working memory. However, non-nappers were more likely to have greater working memory (OR = 4.04; 95% CI: 1.09, 14.92) compared to those having nap duration within ±1SD (0.46-2.18 h/d) of the mean. CONCLUSION: Promoting longer total sleep, including more than nine hours of nighttime sleep, appears important for maintaining healthy adiposity levels in young children. Cessation of napping may be associated with better working memory in preschoolers.

Associations Between the Child Care Environment and Children's In-Care Physical Activity and Sedentary Time.

BACKGROUND: Child care centers are important for children's behaviors. AIMS: To examine the cross-sectional associations between child care environmental characteristics and physical activity and sedentary time in children. METHODS: Participants were 124 toddlers and 118 preschoolers from 19 centers in Alberta and Ontario, Canada, in the supporting Healthy physical AcTive CHildcare setting (HATCH) study. In-care physical activity and sedentary time were assessed using Actigraph accelerometers. Child care environments, including structure (e.g., resources) and process (e.g., activities) quality, were measured using three instruments: (1) the Environment and Policy Assessment and Observation and (2) the Children's Physical Environments Rating Scale, and (iii) the Movement Environment Rating Scale. Mixed models were performed to examine the associations between environmental characteristics and children's sedentary time, light physical activity, and moderate-to-vigorous physical activity. RESULTS: A few structure quality characteristics related to child care policy and indoor environment were associated with higher physical activity and lower sedentary time in toddlers. The overall structure quality (B = 0.04; 95% CI [0.003, 0.08]) and process quality (B = 0.08; 95% CI [0.02, 0.15]) of the child care environment were associated with log moderate-to-vigorous physical activity in preschoolers. Specifically, structure quality characteristics of the outdoor environment and physical activity time, and process quality characteristics relevant to curriculum and pedagogy, were associated with higher physical activity and lower sedentary time in preschoolers. DISCUSSION AND CONCLUSION: The child care structure quality characteristics that are important for children' physical activity and sedentary behavior may vary by age group. Improving the overall process quality, in particular curriculum and pedagogy, of the child care environment, may promote more physical activity in preschoolers.

Sedentary Time and Physical Activity Associations Between Child Care Educators and Children.

INTRODUCTION: This study examines the associations between objectively measured sedentary time and physical activity among child care educators and children in their direct care and aims to determine if the associations differed between toddlers (aged 19-35 months) and preschoolers (aged 36-60 months). METHODS: The participants were educators and children from 19 child care centers in Edmonton and Ottawa, Canada, as part of the Supporting Healthy Active Child Care Settings study. Sedentary time, light-intensity physical activity, and moderate to vigorous-intensity physical activity during child care were measured with accelerometers in 2017-2018. Nap time data were removed for children and educators based on room schedules. Children were matched with the main educator in their room that had the highest total physical activity, resulting in 187 children and 38 educators. Multilevel linear regression models with interaction terms were conducted in 2019. RESULTS: Children engaged in 30.0, 23.1, and 6.9 minutes per hour of sedentary time, light-intensity physical activity, and moderate to vigorous-intensity physical activity, respectively. Educators engaged in 33.5, 23.6, and 2.9 minutes per hour of sedentary time, light-intensity physical activity, and moderate to vigorous-intensity physical activity, respectively. No significant interactions were observed, so age-stratified analyses were not conducted. Each additional 5 minutes per hour of educator sedentary time was significantly associated with 0.5 minutes per hour lower child moderate to vigorous-intensity physical activity. Each additional 5 minutes per hour of educator moderate to vigorous-intensity physical activity was significantly associated with 1.3 minutes per hour higher child moderate to vigorous-intensity physical activity. No other significant observations were observed. CONCLUSIONS: The educators' sedentary time and moderate to vigorous-intensity physical activity may have a small but potentially meaningful influence on children's moderate to vigorous-intensity physical activity because educators directly care for multiple children. Targeting these educator behaviors may be one strategy to increase children's moderate to vigorous-intensity physical activity during child care.

Physical activity and sedentary behaviour of toddlers and preschoolers in child care centres in Alberta, Canada.

OBJECTIVE: To describe duration of physical activity and duration and bouts of sedentary behaviour during child care in a sample of toddlers and preschoolers (19-60 months) from Alberta, Canada, and to examine whether duration and bouts differed among sex, age and parental immigration status groups. METHODS: One hundred and fourteen children aged 19-60 months from eight child care centres throughout Alberta participated. Data were collected at baseline of a study examining revised Alberta Child Care Accreditation Standards. Duration of physical activity (light (LPA), moderate-to-vigorous (MVPA)) and duration and bouts (1-4, 5-9, 10-14, and ≥15 minutes) of sedentary behaviour during child care were accelerometer-derived using 15-second epochs during October/November, 2013. Median [Interquartile ranges] and ANOVAs, accounting for the clustered nature of the data, were calculated. RESULTS: Minutes/hour spent in sedentary behaviour, LPA and MVPA were 36.9 [32.9, 40.7], 18.4 [16.0, 20.9] and 4.2 [2.5, 5.6] respectively. Frequency/hour of sedentary bouts lasting 1-4, 5-9, 10-14 and ≥15 mins were 6.7 [6.1, 7.6], 0.9 [0.6, 1.1], 0.4 [0.2, 0.5] and 0.3 [0.2, 0.4] respectively. Preschoolers participated in less sedentary behaviour and more LPA and MVPA, and had fewer sedentary bouts lasting 10-14 and ≥15 mins compared to toddlers (p < 0.05). CONCLUSION: This is the first Canadian study to report on the duration of physical activity and duration and bouts of sedentary behaviour among both toddlers and preschoolers attending child care centres. These findings suggest child care interventions are needed to increase MVPA and decrease total sedentary behaviour while continuing to promote short sedentary bouts.

Synthesis and characterization of metal sulfide clusters for toxicological studies.

Zinc sulfide clusters were synthesized and characterized at low micromolar concentrations to assess the effect of metal-sulfide ligands on metal toxicity to aquatic organisms in oxic environments. Recommended preparation times are greater than 2 h initial reaction of equimolar sodium sulfide and zinc nitrate, followed by oxic aeration for 3 d. Ionic strength, pH, and anoxic stabilization time were found to be relatively unimportant in controlling the final yield. Adsorptive losses of zinc sulfide (ZnS) clusters to surfaces, however, were significant for a variety of vessel materials and membrane filters. Ionic strength and pH were found to be important factors controlling the extent of adsorptive losses with minimal loss for pHs greater than 9 and for soft waters. The Ag(I), Cu(II), and Hg(II) as metal sulfides completely suppress the analysis of sulfide, whereas Pb(II), Mn(II), and Co(II) partially suppress the analysis of sulfide by the methylene blue technique. Ultraviolet and fluorescence spectra are shown for synthesized ZnS clusters.

Characterization of AQX-1125, a small-molecule SHIP1 activator: Part 1. Effects on inflammatory cell activation and chemotaxis in vitro and pharmacokinetic characterization in vivo.

BACKGROUND: The SH2-containing inositol-5'-phosphatase 1 (SHIP1) metabolizes PI(3,4,5)P3 to PI(3,4)P2. SHIP1-deficient mice exhibit progressive inflammation. Pharmacological activation of SHIP1 is emerging as a potential therapy for pulmonary inflammatory diseases. Here we characterize the efficacy of AQX-1125, a small-molecule SHIP1 activator currently in clinical development. EXPERIMENTAL APPROACH: The effects of AQX-1125 were tested in several in vitro assays: on enzyme catalytic activity utilizing recombinant human SHIP1, on Akt phosphorylation in SHIP1-proficient and SHIP1-deficient cell lines, on cytokine release in murine splenocytes, on human leukocyte chemotaxis using modified Boyden chambers and on ß-hexosaminidase release from murine mast cells. In addition, pharmacokinetic and drug distribution studies were performed in rats and dogs. RESULTS: AQX-1125 increased the catalytic activity of human recombinant SHIP1, an effect, which was absent after deletion of the C2 region. AQX-1125 inhibited Akt phosphorylation in SHIP1-proficient but not in SHIP1-deficient cells, reduced cytokine production in splenocytes, inhibited the activation of mast cells and inhibited human leukocyte chemotaxis. In vivo, AQX-1125 exhibited >80% oral bioavailability and >5 h terminal half-life. CONCLUSIONS: Consistent with the role of SHIP1 in cell activation and chemotaxis, the SHIP1 activator AQX-1125 inhibits Akt phosphorylation, inflammatory mediator production and leukocyte chemotaxis in vitro. The in vitro effects and the pharmacokinetic properties of the compound make it a suitable candidate for in vivo testing in various models of inflammation.

The biotic ligand model and a cellular approach to class B metal aquatic toxicity.

The biotic ligand model (BLM) and a cellular molecular mechanism approach represent two approaches to the correlation of metal speciation with observed toxicity to aquatic organisms. The two approaches are examined in some detail with particular reference to class B, or soft metals. Kinetic arguments are presented to suggest situations that can arise where the BLM criterion of equilibrium between all metal species in the bulk solution and the biotic ligand may not be satisfied and what might the consequences be to BLM predictive capability. Molecular mechanisms of toxicity are discussed in terms of how a class B metal might enter a cell, how it is distributed in a cell, and how the cell might respond to the unwanted metal. Specific examples are given for copper as an organism trace essential metal, which is toxic in excess, and for silver, a non-essential metal. As class B metals all bind strongly to sulfur, regulation of these metals requires that all S(II-) species be accounted for in aquatic systems, even under oxic conditions.