82 research outputs found
Success in reading… what’s the meaning? The relationship between changes in children’s aerobic fitness and language processing
Recent studies have demonstrated that participation in physical activity (PA) programs is a viable means for improving children’s cardiovascular health, including body weight maintenance and increases in aerobic fitness. Additionally, such health outcomes appear to be related to better academic achievement, as well as the underlying cognitive processes governing such performance (i.e., inhibitory control, working memory, etc.). Event-related brain potentials (ERPs) have been instrumental for uncovering further details about the relationship between aerobic fitness and individual aspects of cognitive control; however, very few studies have employed this technique to investigate children’s language processing.
Accordingly, children participated in an after-school PA program over the 9-month academic calendar, while outcome measures were assessed at both pre- and post-test using repeated measures multivariate analysis of variance. In addition to aerobic fitness, demographics, and standardized academic achievement scores, outcome measures included children’s performance on a sentence comprehension task while ERPs were recorded. The N400 and P600 ERP components were of particular interest and provided further information about children’s semantic (i.e., meaning) processing and access to word-related knowledge, as well as their ability to detect syntactic ambiguities and allocate resources towards re-analysis and repair. Secondary hierarchical regression analyses were also conducted to determine the relationship between changes in aerobic fitness and children’s post-test academic performance after controlling for pre-test fitness levels and academic scores, important demographic variables (i.e., age, sex, socioeconomic status [SES], BMI, IQ [intelligence quotient]), and N400/P600 amplitude. Lastly, to replicate prior work, twenty-eight children residing at the lower (≤ 30th percentile) and higher (≥ 70th percentile) ends of the fitness distribution were matched on age, sex, SES, and IQ, and outcome measures were compared.
Contrary to our hypothesis, children in the intervention group did not exhibit greater increases in aerobic fitness compared to the wait-list control group, yet children in the intervention did display smaller increases in weight and BMI. Given the lack of fitness change, it was not surprising that the intervention group did not experience greater academic gains or increases in sentence performance, nor were there any group ERP differences; however, increases in aerobic fitness were observed among the wave 1 control group (albeit unexpectedly). Interestingly, compared to other participants, greater improvements in academic achievement and sentence performance were witnessed among children in wave 1, with larger increases in academic composite scores occurring primarily in the wave 1 control group versus children in the intervention. Regression analyses also revealed a marginal association between increases in aerobic fitness and greater improvements on standardized tests of reading. This effect was not mediated by the inclusion of children’s N400 and P600 amplitude, which were both independently related to academic performance involving language-based abilities (note: children in wave 1 also had overall larger N400 amplitude compared to other waves). Finally, exploratory comparisons between higher and lower fit children, matched on important demographics, partially replicated findings from an earlier study. Despite no differences in academic performance, higher fit children demonstrated greater sentence task accuracy as well as greater overall N400 amplitude compared to lower fit children (replicating prior findings), yet lower fit children displayed shorter latencies (opposing prior findings).
The current results extend previous work by providing evidence that not only higher aerobic fitness levels, but also increases in children’s fitness may be related to superior performance on standardized academic achievement measures. Future studies will be necessary to determine if this relationship is indeed selective to reading, or to a broader array of academic domains. Future studies should also continue to design and implement effective PA programs or other strategies that result in the greatest gains for aerobic fitness, especially in terms of targeting and influencing the vast majority of children. Finally, although ERP latency and amplitude changed little over the course of a year and were not associated with changes in fitness, certain component characteristics do appear to be important markers of children’s academic achievement, which may reveal further details if tracked over a longer period of development. Such information would continue to aid researchers in understanding the impact that aerobic fitness and other aspects of cardiovascular health have on children’s cognitive and academic performance, and ensure that programs are optimally designed to deliver the overall greatest possible benefits for children’s health and well-being
The ALMaQUEST survey – III. Scatter in the resolved star-forming main sequence is primarily due to variations in star formation efficiency
Using a sample of 11,478 spaxels in 34 galaxies with molecular gas, star formation and stellar maps taken from the ALMA-MaNGA QUEnching and STar formation (ALMaQUEST) survey, we investigate the parameters that correlate with variations in star formation rates on kpc scales. We use a combination of correlation statistics and an artificial neural network to quantify the parameters that drive both the absolute star formation rate surface density (Sigma_SFR), as well as its scatter around the resolved star forming main sequence (Delta Sigma_SFR). We find that Sigma_SFR is primarily regulated by molecular gas surface density (Sigma_H2) with a secondary dependence on stellar mass surface density (Sigma_*), as expected from an `extended Kennicutt-Schmidt relation'. However, Delta Sigma_SFR is driven primarily by changes in star formation efficiency (SFE), with variations in gas fraction playing a secondary role. Taken together, our results demonstrate that whilst the absolute rate of star formation is primarily set by the amount of molecular gas, the variation of star formation rate above and below the resolved star forming main sequence (on kpc scales) is primarily due to changes in SFE
Weakly- and Semi-Supervised Panoptic Segmentation
We present a weakly supervised model that jointly performs both semantic- and
instance-segmentation -- a particularly relevant problem given the substantial
cost of obtaining pixel-perfect annotation for these tasks. In contrast to many
popular instance segmentation approaches based on object detectors, our method
does not predict any overlapping instances. Moreover, we are able to segment
both "thing" and "stuff" classes, and thus explain all the pixels in the image.
"Thing" classes are weakly-supervised with bounding boxes, and "stuff" with
image-level tags. We obtain state-of-the-art results on Pascal VOC, for both
full and weak supervision (which achieves about 95% of fully-supervised
performance). Furthermore, we present the first weakly-supervised results on
Cityscapes for both semantic- and instance-segmentation. Finally, we use our
weakly supervised framework to analyse the relationship between annotation
quality and predictive performance, which is of interest to dataset creators.Comment: ECCV 2018. The first two authors contributed equall
Acute exercise facilitates brain function and cognition in children who need it most: An ERP study of individual differences in inhibitory control capacity
AbstractThe present study examined the effects of moderate-intensity aerobic exercise on aspects of cognitive control in two groups of children categorized by higher- and lower-task performance. Event-related brain potentials (ERPs) were collected in 40 preadolescent children during a modified flanker task following 20min of treadmill walking and seated rest on separate occasions. Participants were bifurcated into two groups based on task performance following the resting session. Findings revealed that following exercise, higher-performers maintained accuracy and exhibited no change in P3 amplitude compared to seated rest. Lower-performers demonstrated a differential effect, such that accuracy measures improved, and P3 amplitude increased following exercise. Lastly, both groups displayed smaller N2 amplitude and shorter P3 latency following exercise, suggesting an overall facilitation in response conflict and the speed of stimulus classification. The current findings replicate prior research reporting the beneficial influence of acute aerobic exercise on cognitive performance in children. However, children with lower inhibitory control capacity may benefit the most from single bouts of exercise. These data are among the first to demonstrate the differential effect of physical activity on individuals who vary in inhibitory control, and further support the role of aerobic exercise for brain health during development
The ALMaQUEST Survey - II. What drives central starbursts at z ∼ 0?
Starburst galaxies have elevated star formation rates (SFRs) for their stellar mass. In Ellison et al., we used integral field unit maps of SFR surface density (ΣSFR) and stellar mass surface density (Σ⋆) to show that starburst galaxies in the local universe are driven by SFRs that are preferentially boosted in their central regions. Here, we present molecular gas maps obtained with the Atacama Large Millimeter Array (ALMA) observatory for 12 central starburst galaxies at z ∼ 0 drawn from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey. The ALMA and MaNGA data are well matched in spatial resolution, such that the ALMA maps of molecular gas surface density (ΣH2) can be directly compared with MaNGA maps at kpc-scale resolution. The combination of ΣH2, Σ⋆ and ΣSFR at the same resolution allow us to investigate whether central starbursts are driven primarily by enhancements in star formation efficiency (SFE) or by increased gas fractions. By computing offsets from the resolved Kennicutt-Schmidt relation (ΣH2 versus ΣSFR) and the molecular gas main sequence (Σ⋆ versus ΣH2), we conclude that the primary driver of the central starburst is an elevated SFE. We also show that the enhancement in ΣSFR is accompanied by a dilution in O/H, consistent with a triggering that is induced by metal poor gas inflow. These observational signatures are found in both undisturbed (9/12 galaxies in our sample) and recently merged galaxies, indicating that both interactions and secular mechanisms contribute to central starbursts
The Effect of Galaxy Interactions on Molecular Gas Properties
© 2018. The American Astronomical Society. All rights reserved.Galaxy interactions are often accompanied by an enhanced star formation rate (SFR). Since molecular gas is essential for star formation, it is vital to establish whether and by how much galaxy interactions affect the molecular gas properties. We investigate the effect of interactions on global molecular gas properties by studying a sample of 58 galaxies in pairs and 154 control galaxies. Molecular gas properties are determined from observations with the JCMT, PMO, and CSO telescopes and supplemented with data from the xCOLD GASS and JINGLE surveys at 12CO(1-0) and 12CO(2-1). The SFR, gas mass (), and gas fraction (f gas) are all enhanced in galaxies in pairs by ∼2.5 times compared to the controls matched in redshift, mass, and effective radius, while the enhancement of star formation efficiency (SFE ≡SFR/) is less than a factor of 2. We also find that the enhancements in SFR, and f gas, increase with decreasing pair separation and are larger in systems with smaller stellar mass ratio. Conversely, the SFE is only enhanced in close pairs (separation <20 kpc) and equal-mass systems; therefore, most galaxies in pairs lie in the same parameter space on the SFR- plane as controls. This is the first time that the dependence of molecular gas properties on merger configurations is probed statistically with a relatively large sample and a carefully selected control sample for individual galaxies. We conclude that galaxy interactions do modify the molecular gas properties, although the strength of the effect is dependent on merger configuration.Peer reviewedFinal Accepted Versio
Moderate-to-vigorous physical activity, indices of cognitive control, and academic achievement in preadolescents
To assess whether preadolescents' objectively measured moderate-to-vigorous physical activity (MVPA) is associated with cognitive control and academic achievement, independent of aerobic fitness.A sample of 74 children (Meanage = 8.64 years, SD = .58, 46% girls) were included in the analyses. Daily MVPA (min/d) was measured over 7 days using ActiGraph wGT3X+ accelerometer. Aerobic fitness was measured using a maximal graded exercise test and expressed as maximal oxygen uptake (mL*kg(-1)*min(-1)). Inhibitory control was measured with a modified Eriksen flanker task (reaction time and accuracy), and working memory with an Operation Span Task (accuracy scores). Academic achievement (in reading, mathematics, and spelling) was expressed as standardized scores on the Kaufman Test of Educational Achievement. The relationships were assessed using hierarchical regression models adjusting for aerobic fitness and other covariates.No significant associations were found between MVPA and inhibition, working memory, or academic achievement. Aerobic fitness was positively associated with inhibitory control (P = .02) and spelling (P = .04) but not with other cognitive or academic variables (all P > .05).Aerobic fitness, rather than daily MVPA, is positively associated with childhood ability to manage perceptual interference and spelling. Further research into the associations between objectively measured MVPA and cognitive and academic outcomes in children while controlling for important covariates is needed
Physical activity and academic achievement across the curriculum (A + PAAC): rationale and design of a 3-year, cluster-randomized trial
Abstract
Background
Improving academic achievement and reducing the rates of obesity in elementary school students are both of considerable interest. Increased physical activity during academic instruction time during school offers a potential intervention to address both issues. A program titled “Physical Activity Across the Curriculum” (PAAC) was developed in which classroom teachers in 22 elementary schools were trained to deliver academic instruction using physical activity with a primary aim of preventing increased BMI. A secondary analysis of data assessed the impact of PAAC on academic achievement using the Weschler Individual Achievement Test-II and significant improvements were shown for reading, math and spelling in students who participated in PAAC. Based on the results from PAAC, an adequately powered trial will be conducted to assess differences in academic achievement between intervention and control schools called, “Academic Achievement and Physical Activity Across the Curriculum (A + PAAC).”
Methods/design
Seventeen elementary schools were cluster randomized to A + PAAC or control for a 3-year trial. Classroom teachers were trained to deliver academic instruction through moderate-to-vigorous physical activity with a target of 100+ minutes of A + PAAC activities per week. The primary outcome measure is academic achievement measured by the Weschler Individual Achievement Test-III, which was administered at baseline (Fall 2011) and will be repeated in the spring of each year by assessors blinded to condition. Potential mediators of any association between A + PAAC and academic achievement will be examined on the same schedule and include changes in cognitive function, cardiovascular fitness, daily physical activity, BMI, and attention-to-task. An extensive process analysis will be conducted to document the fidelity of the intervention. School and student recruitment/randomization, teacher training, and baseline testing for A + PAAC have been completed. Nine schools were randomized to the intervention and 8 to control. A random sample of students in each school, stratified by gender and grade (A + PAAC = 370, Control = 317), was selected for outcome assessments from those who provided parental consent/child assent. Baseline data by intervention group are presented.
Discussion
If successful, the A + PAAC approach could be easily and inexpensively scaled and disseminated across elementary schools to improve both educational quality and health. Funding source: R01- DK85317. Trial registration: US NIH Clinical Trials, http://NCT01699295.Peer Reviewe
Moderate-to-Vigorous Physical Activity, Indices of Cognitive Control, and Academic Achievement in Preadolescents.
OBJECTIVE: To assess whether preadolescents' objectively measured moderate-to-vigorous physical activity (MVPA) is associated with cognitive control and academic achievement, independent of aerobic fitness. STUDY DESIGN: A sample of 74 children (Meanage = 8.64 years, SD = .58, 46% girls) were included in the analyses. Daily MVPA (min/d) was measured over 7 days using ActiGraph wGT3X+ accelerometer. Aerobic fitness was measured using a maximal graded exercise test and expressed as maximal oxygen uptake (mL*kg(-1)*min(-1)). Inhibitory control was measured with a modified Eriksen flanker task (reaction time and accuracy), and working memory with an Operation Span Task (accuracy scores). Academic achievement (in reading, mathematics, and spelling) was expressed as standardized scores on the Kaufman Test of Educational Achievement. The relationships were assessed using hierarchical regression models adjusting for aerobic fitness and other covariates. RESULTS: No significant associations were found between MVPA and inhibition, working memory, or academic achievement. Aerobic fitness was positively associated with inhibitory control (P = .02) and spelling (P = .04) but not with other cognitive or academic variables (all P > .05). CONCLUSIONS: Aerobic fitness, rather than daily MVPA, is positively associated with childhood ability to manage perceptual interference and spelling. Further research into the associations between objectively measured MVPA and cognitive and academic outcomes in children while controlling for important covariates is needed.This study was funded in part by a grant from the Eunice Kennedy Shriver National Institute of Child Health and Human Development HD069381 to Charles Hillman and Arthur Kramer, which also funded the work of Bonnie Hemrick and Jeanine Bensken. Lauren Sherar and Dale Esliger were funded by the National Institute for Health Research (NIHR) Diet, Lifestyle & Physical Activity Biomedical Research Unit, University Hospitals of Leicester; the National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care – East Midlands (NIHR CLAHRC – EM); Lauren Raine was funded by the National Institute for Agriculture under the Illinois Transdisciplinary Obesity Prevention Program grant (2011-67001-30101); the Hatch Project #ILLU-971-358. The manuscript formed a part of a PhD research by Dominika Pindus funded by the School of Sport, Exercise and Health Sciences, Loughborough University. No industry relations were noted for Bonnie Hemrick or Jeanine Bensken. Conflict of interests: Neither authors nor individuals listed in the acknowledgements report any potential, perceived or real conflict of interests in relation to this manuscript.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.jpeds.2016.02.04
The Human Frontal Oculomotor Cortical Areas Contribute Asymmetrically to Motor Planning in a Gap Saccade Task
BACKGROUND: Saccadic eye movements are used to rapidly align the fovea with the image of objects of interest in peripheral vision. We have recently shown that in children there is a high preponderance of quick latency but poorly planned saccades that consistently fall short of the target goal. The characteristics of these multiple saccades are consistent with a lack of proper inhibitory control of cortical oculomotor areas on the brainstem saccade generation circuitry. METHODOLOGY/PRINCIPAL FINDINGS: In the present paper, we directly tested this assumption by using single pulse transcranial magnetic stimulation (TMS) to transiently disrupt neuronal activity in the frontal eye fields (FEF) and supplementary eye fields (SEF) in adults performing a gap saccade task. The results showed that the incidence of multiple saccades was increased for ispiversive but not contraversive directions for the right and left FEF, the left SEF, but not for the right SEF. Moreover, this disruption was most substantial during the approximately 50 ms period around the appearance of the peripheral target. A control condition in which the dorsal motor cortex was stimulated demonstrated that this was not due to any non-specific effects of the TMS influencing the spatial distribution of attention. CONCLUSIONS/SIGNIFICANCE: Taken together, the results are consistent with a direction-dependent role of the FEF and left SEF in delaying the release of saccadic eye movements until they have been fully planned
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