Agreement between activPAL and ActiGraph for assessing children's sedentary time

BackgroundAccelerometers have been used to determine the amount of time that children spend sedentary. However, as time spent sitting may be detrimental to health, research is needed to examine whether accelerometer sedentary cut-points reflect the amount of time children spend sitting. The aim of this study was to: a) examine agreement between ActiGraph (AG) cut-points for sedentary time and objectively-assessed periods of free-living sitting and sitting plus standing time using the activPAL (aP); and b) identify cut-points to determine time spent sitting and sitting plus standing.MethodsForty-eight children (54% boys) aged 8&ndash;12 years wore a waist-mounted AG and thigh-mounted aP for two consecutive school days (9&ndash;3:30 pm). AG data were analyzed using 17 cut-points between 50&ndash;850 counts&middot;min&minus;1 in 50 counts&middot;min&minus;1 increments to determine sedentary time during class-time, break time and school hours. Sitting and sitting plus standing time were obtained from the aP for these periods. Limits of agreement were computed to evaluate bias between AG50 to AG850 sedentary time and sitting and sitting plus standing time. Receiver Operator Characteristic (ROC) analyses identified AG cutpoints that maximized sensitivity and specificity for sitting and sitting plus standing time.ResultsThe smallest mean bias between aP sitting time and AG sedentary time was AG150 for class time (3.8 minutes), AG50 for break time (&minus;0.8 minutes), and AG100 for school hours (&minus;5.2 minutes). For sitting plus standing time, the smallest bias was observed for AG850. ROC analyses revealed an optimal cut-point of 96 counts&middot;min&minus;1 (AUC = 0.75) for sitting time, which had acceptable sensitivity (71.7%) and specificity (67.8%). No optimal cut-point was obtained for sitting plus standing (AUC = 0.51).ConclusionsEstimates of free-living sitting time in children during school hours can be obtained using an AG cut-point of 100 counts&middot;min&minus;1. Higher sedentary cut-points may capture both sitting and standing time.<br /

Criterion validity of the activPAL™ and ActiGraph for assessing children\u27s sitting and standing time in a school classroom setting

BACKGROUND: Few studies have investigated the accuracy of the ActiGraph (AG) GTX3 accelerometer for assessing children\u27s sitting and standing time. The activPAL (aP) has an inclinometer function that enables it to distinguish between sitting/lying and standing; however, its accuracy for assessing sitting and standing in older children is unknown. This study validated the accuracy of these devices for estimating sitting and standing time in a school classroom against a criterion measure of direct observation (DO). FINDINGS: Forty children in grades 5-7 wore both devices while being video recorded during two school lessons. AG and aP data were simultaneously collected in 15-s epochs. Individual participant DO and aP data were recorded as total time spent sitting/lying, standing and stepping. AG data were converted into time spent sitting and standing using previously established cut-points. Compared with DO, the aP underestimated sitting time (mean bias&thinsp;=&thinsp;-1.9 min, 95 % LoA&thinsp;=&thinsp;-8.9 to 5.2 min) and overestimated standing time (mean bias&thinsp;=&thinsp;1.8 min, 95% LoA&thinsp;=&thinsp;-9.6 to 13.3 min). The best-performing AG cut-point across both sitting and standing (&lt;75 counts/15 s) was more accurate than the aP, underestimating sitting time (mean bias&thinsp;=&thinsp;-0.8 min, 95 % LoA&thinsp;=&thinsp;-10.5 to 9.9 min) and standing time (mean bias&thinsp;=&thinsp;-0.4 min, 95% LoA&thinsp;=&thinsp;-9.8 to 9.1 min), but was less precise as evidenced by wider LoAs and poorer correlations with DO (sitting r&thinsp;=&thinsp;0.86 aP vs 0.80 AG; standing r&thinsp;=&thinsp;0.78 aP vs 0.60 AG). CONCLUSIONS: The aP demonstrated good accuracy and precision for assessing free-living sitting and standing time in classroom settings. The AG was most accurate using a cut-point of&thinsp;&lt;&thinsp;75 counts/15 s. Further studies should validate the monitors in settings with greater inter- and intra-individual variation in movement patterns

Equipping future teachers with innovative strategies that increase physical activity in the classroom : A hybrid implementation trial across three Australian universities

Introduction: TransformEd targets initial teacher education (ITE) to equip future teachers with innovative strategies that increase physical activity in the Primary school classroom. Methods: This hybrid implementation-effectiveness trial investigated the effects of the TransformEd program when embedded in ITE degrees at two Australian universities (University 1 Single Unit offering; University 2 Dual Unit offering) over a 12-week period, on pre-service teachers’ perceived competence, confidence, and willingness to deliver active pedagogies, in comparison with a third ‘usual practice’ control university. Results: There was a favourable intervention effect on the total teacher perceptions score among pre-service teachers in University 1 compared to the control group pre-service teachers. Further, there was a significant intervention effect on reduced perceived barriers to active strategies in University 1, and a significant increase in perceived effects of active strategies on Primary school student outcomes in University 2. Qualitative data suggested the program strengthened the connection between theory and practice (i.e., how pre-service teachers are educated in university and the way they teach in Primary schools). The program was motivating to both lecturers and pre-service teachers, resulted in them reflecting on their own teaching practice, and helped with pre-service teacher engagement. Discussion: Recommendations for improvement included stronger and more explicit alignment with the Australian Professional Standards for Teachers

Outcomes for gastrostomy‐fed children and their parents : qualitative findings from the ‘Your Tube’ study

Aim To identify child and parent outcomes relevant to having a gastrostomy, and to specify outcomes believed to be particularly salient to type of diet (formula vs blended food). Method Twenty parents, two children (both 12y), and 41 professionals (dietitians [n=10]; nurses [n=12]; paediatricians [n=12]; speech and language therapists [n=7)]) were recruited. Parents and children were interviewed; professionals participated in focus groups. Children (2–18y) represented included those on formula (n=11), blended-food (n=7), and mixed (n=2) diets. All had been tube-fed for at least 6 months. Neurological, genetic, and metabolic conditions were represented. Results Participants identified a range of children’s outcomes relevant to a gastrostomy, including physical health, gastrointestinal symptoms, sleep, and time spent feeding. The children described experiences of exclusion caused by being tube-fed. Time, sleep, and emotional health were regarded as most salient to understanding parents’ gastrostomy outcomes. Participants believed type of diet would most likely effect gastrointestinal symptoms, time spent feeding, sleep, and physical health. Interpretation Findings indicate a number of refinements to, and allow further specification of, the current ‘initial’ core outcome set for tube-fed children. Findings also have implications for choice of outcomes measures. Further qualitative research with children and young people is needed

Light-intensity physical activity and cardiometabolic biomarkers in US adolescents

BackgroundThe minimal physical activity intensity that would confer health benefits among adolescents is unknown. The purpose of this study was to examine the associations of accelerometer-derived light-intensity (split into low and high) physical activity, and moderate- to vigorous-intensity physical activity with cardiometabolic biomarkers in a large population-based sample.MethodsThe study is based on 1,731 adolescents, aged 12&ndash;19 years from the 2003/04 and 2005/06 National Health and Nutrition Examination Survey. Low light-intensity activity (100&ndash;799 counts/min), high light-intensity activity (800 counts/min to &lt;4 METs) and moderate- to vigorous-intensity activity (&ge;4 METs, Freedson age-specific equation) were accelerometer-derived. Cardiometabolic biomarkers, including waist circumference, systolic blood pressure, diastolic blood pressure, HDL-cholesterol, and C-reactive protein were measured. Triglycerides, LDL- cholesterol, insulin, glucose, and homeostatic model assessments of &beta;-cell function (HOMA-%B) and insulin sensitivity (HOMA-%S) were also measured in a fasting sub-sample (n=807).ResultsAdjusted for confounders, each additional hour/day of low light-intensity activity was associated with 0.59 (95% CI: 1.18&ndash;0.01) mmHG lower diastolic blood pressure. Each additional hour/day of high light-intensity activity was associated with 1.67 (2.94&ndash;0.39) mmHG lower diastolic blood pressure and 0.04 (0.001&ndash;0.07) mmol/L higher HDL-cholesterol. Each additional hour/day of moderate- to vigorous-intensity activity was associated with 3.54 (5.73&ndash;1.35) mmHG lower systolic blood pressure, 5.49 (1.11&ndash;9.77)% lower waist circumference, 25.87 (6.08&ndash;49.34)% lower insulin, and 16.18 (4.92&ndash;28.53)% higher HOMA-%S.ConclusionsTime spent in low light-intensity physical activity and high light-intensity physical activity had some favorable associations with biomarkers. Consistent with current physical activity recommendations for adolescents, moderate- to vigorous-intensity activity had favorable associations with many cardiometabolic biomarkers. While increasing MVPA should still be a public health priority, further studies are needed to identify dose-response relationships for light-intensity activity thresholds to inform future recommendations and interventions for adolescents.</div

Clathrin and LRP-1-Independent Constitutive Endocytosis and Recycling of uPAR

Background: The urokinase receptor (uPAR/CD87) is highly expressed in malignant tumours. uPAR, as a GPI anchored protein, is preferentially located at the cell surface, where it interacts with its ligands urokinase (uPA) and the extracellular matrix protein vitronectin, thus promoting plasmin generation, cell-matrix interactions and intracellular signalling events. Interaction with a complex formed by uPA and its inhibitor PAI-1 induces cell surface down regulation and recycling of the receptor via the clathrin-coated pathway, a process dependent on the association to LRP-1. Methodology/Principal Findings: In this study, we have found that along with the ligand-induced down-regulation, uPAR also internalizes and recycles constitutively through a second pathway that is independent of LRP-1 and clathrin but shares some properties with macropinocytosis. The ligand-independent route is amiloride-sensitive, does not require uPAR partitioning into lipid rafts, is independent of the activity of small GTPases RhoA, Rac1 and Cdc42, and does not require PI3K activity. Constitutively endocytosed uPAR is found in EEA1 positive early/recycling endosomes but does not reach lysosomes in the absence of ligands. Electron microscopy analysis reveals the presence of uPAR in ruffling domains at the cell surface, in macropinosome-like vesicles and in endosomal compartments. Conclusions/Significance: These results indicate that, in addition to the ligand-induced endocytosis of uPAR, efficient surface expression and membrane trafficking might also be driven by an uncommon macropinocytic mechanism couple

No evidence that footedness in pheasants influences cognitive performance in tasks assessing colour discrimination and spatial ability

The differential specialization of each side of the brain facilitates the parallel processing of information and has been documented in a wide range of animals. Animals that are more lateralized as indicated by consistent preferential limb use are commonly reported to exhibit superior cognitive ability as well as other behavioural advantages.We assayed the lateralization of 135 young pheasants (Phasianus colchicus), indicated by their footedness in a spontaneous stepping task, and related this measure to individual performance in either 3 assays of visual or spatial learning and memory. We found no evidence that pronounced footedness enhances cognitive ability in any of the tasks. We also found no evidence that an intermediate footedness relates to better cognitive performance. This lack of relationship is surprising because previous work revealed that pheasants have a slight population bias towards right footedness, and when released into the wild, individuals with higher degrees of footedness were more likely to die. One explanation for why extreme lateralization is constrained was that it led to poorer cognitive performance, or that optimal cognitive performance was associated with some intermediate level of lateralization. This stabilizing selection could explain the pattern of moderate lateralization that is seen in most non-human species that have been studied. However, we found no evidence in this study to support this explanation