339 research outputs found
Importance of fundamental movement skills to predict technical skills in youth grassroots soccer:a machine learning approach
This study determined the contributors to soccer technical skill in grassroots youth soccer players using a machine learning approach. One hundred and sixty two boys aged 7-14 (Mean ± SD = 10.5 ± 2.1) years, who were regularly engaged in grassroots soccer undertook assessments of anthropometry and maturity offset (the time from age at peak height velocity (APHV)), Fundamental Movement skills (FMS), perceived physical competence, and physical fitness and technical soccer skill using the university of Ghent (UGent) dribbling test. Coaches rated playerâs overall soccer skill for their age. Statistical analysis was undertaken, using machine learning models to predict technical skill from the other variables. A stepwise recursive feature elimination with a 5-fold cross-validation (RFECV) method was used to eliminate the worst performing features and both L1 and L2 regularisation were evaluated during the process. Five models (linear, ridge, lasso, random forest, boosted trees) were then used in a heuristic approach using a small subset of suitable algorithms to achieve a reasonable level of accuracy within a reasonable time frame) to make predictions and compare them to a test set to understand the predictive capabilities of the models. Results from the machine learning analysis indicated that total FMS score (0-50) was the most important feature in predicting technical soccer skill followed by coach rating of child skill for their age, years playing experience and APHV. Using a random forest, technical skill could be predicted with 99% accuracy in boys who play grassroots soccer, with FMS being the most important contributor
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1995 Site environmental report Sandia National Laboratories, Albuquerque, New Mexico
This 1995 report contains data from routine radiological and non-radiological environmental monitoring activities. Summaries of significant environmental compliance programs in progress, such as National Environmental Policy Act documentation, environmental permits, environmental restoration and various waste management programs at Sandia National Laboratories in Albuquerque, New Mexico, are included
A systematic review of tools designed for teacher proxy-report of childrenâs physical literacy or constituting elements
Abstract Background Physical literacy (PL) in childhood is essential for a healthy active lifestyle, with teachers playing a critical role in guiding its development. Teachers can assist children to acquire the skills, confidence, and creativity required to perform diverse movements and physical activities. However, to detect and directly intervene on the aspects of childrenâs PL that are suboptimal, teachers require valid and reliable measures. This systematic review critically evaluates the psychometric properties of teacher proxy-report instruments for assessing one or more of the 30 elements within the four domains (physical, psychological, cognitive, social) of the Australian Physical Literacy Framework (APLF), in children aged 5â12âyears. Secondary aims were to: examine alignment of each measure (and relevant items) with the APLF and provide recommendations for teachers in assessing PL. Methods Seven electronic databases (Academic Search Complete, CINAHL Complete, Education Source, Global Health, MEDLINE Complete, PsycINFO, and SPORTDiscus) were systematically searched originally in October 2019, with an updated search in April 2021. Eligible studies were peer-reviewed English language publications that sampled a population of children with mean age between 5 and 12âyears and focused on developing and evaluating at least one psychometric property of a teacher proxy-report instrument for assessing one or more of the 30 APLF elements. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance was followed for the conduct and reporting of this review. The methodological quality of included studies and quality of psychometric properties of identified tools were evaluated using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidance. Alignment of each measure (and relevant items) with the APLF domains and 30 elements was appraised. Results Database searches generated 61,412 citations; reduced to 41 studies that evaluated the psychometric properties of 24 teacher proxy-report tools. Six tools were classified as single domain measures (i.e. assessing a single domain of the APLF), eleven as dual-domain measures, and seven as tri-domain measures. No single tool captured all four domains and 30 elements of the APLF. Tools contained items that aligned with all physical, psychological, and social elements; however, four cognitive elements were not addressed by any measure. No tool was assessed for all nine psychometric properties outlined by COSMIN. Included studies reported a median of 3 out of nine psychometric properties. Most reported psychometric properties were construct validity (nâ=â32; 78% of studies), structural validity (nâ=â26; 63% of studies), and internal consistency (nâ=â25; 61% of studies). There was underreporting of content validity, cross-cultural validity, measurement error, and responsiveness. Psychometric data across tools were mostly indeterminate for construct validity, structural validity, and internal consistency. Conclusions There is limited evidence to fully support the use of a specific teacher proxy-report tool in practice. Further psychometric testing and detailed reporting of methodological aspects in future validity and reliability studies is needed. Tools have been designed to assess some elements of the framework. However, no comprehensive teacher proxy-report tool exists to assess all 30 elements of the APLF, demonstrating the need for a new tool. It is our recommendation that such tools be developed and psychometrically tested. Trial registration This systematic review was registered in the PROSPERO international prospective register of systematic reviews, with registration number CRD42019130936
Earth observation and geospatial data can predict the relative distribution of village level poverty in the Sundarban Biosphere Reserve, India
There is increasing interest in leveraging Earth Observation (EO) and geospatial data to predict and map aspects of socioeconomic conditions to support survey and census activities. This is particularly relevant for the frequent monitoring required to assess progress towards the UNs' Sustainable Development Goals (SDGs). The Sundarban Biosphere Reserve (SBR) is a region of international ecological importance, containing the Indian portion of the world's largest mangrove forest. The region is densely populated and home to over 4.4 million people, many living in chronic poverty with a strong dependence on nature-based rural livelihoods. Such livelihoods are vulnerable to frequent natural hazards including cyclone landfall and storm surges. In this study we examine associations between environmental variables derived from EO and geospatial data with a village level multidimensional poverty metric using random forest machine learning, to provide evidence in support of policy formulation in the field of poverty reduction. We find that environmental variables can predict up to 78% of the relative distribution of the poorest villages within the SBR. Exposure to cyclone hazard was the most important variable for prediction of poverty. The poorest villages were associated with relatively small areas of rural settlement (<âŒ30%), large areas of agricultural land (>âŒ50%) and moderate to high cyclone hazard. The poorest villages were also associated with less productive agricultural land than the wealthiest. Analysis suggests villages with access to more diverse livelihood options, and a smaller dependence on agriculture may be more resilient to cyclone hazard. This study contributes to the understanding of poverty-environment dynamics within Low-and middle-income countries and the associations found can inform policy linked to socio-environmental scenarios within the SBR and potentially support monitoring of work towards SDG1 (No Poverty) across the region.</p
Higher Resonance Contamination of pi NN Couplings Obtained Via the Three-Point Function Method in QCD Sum Rules
We investigate the size of potential higher pseudoscalar resonance
contaminations of the estimates of isospin-conserving and isospin-violating
couplings obtained using the 3-point function method in QCD sum rules.
For the isospin-conserving case it is shown that conventional models of the
isovector pseudoscalar spectral function imply resonance decay constants large
enough to create significant contaminations, and that assuming these models are
incorrect, and that the decay constants are actually much smaller, implies
physically implausible values for the flavor-breaking quark condensate ratios.
For the isospin-violating case it is shown explicitly that such resonance
contamination is unavoidably present and precludes using the 3-point function
method as a means of estimating the at present unmeasured isospin-violating
couplings.Comment: 8 page
Effect of the Task, Visual and Semantic Context on Word Target Detection
Abstract. Although being a daily task, the search for a word among others words is a new research domain we investigated in order to find the kinds contextual factors that can facilitate semantic oriented visual search. We report two experiments assessing task context, visual context and semantic context. Some of our results are found to be those of classical non-semantic visual search, while others show the impact of the semantic context. Basic recommendations can be find out for Human-Computer conception and cognitive chronometry methodology.
Phenomenology of non-standard Z couplings in exclusive semileptonic b -> s transitions
The rare decays , and
are analyzed in a generic scenario where New Physics effects
enter predominantly via penguin contributions. We show that this
possibility is well motivated on theoretical grounds, as the vertex
is particularly susceptible to non-standard dynamics. In addition, such a
framework is also interesting phenomenologically since the coupling
is rather poorly constrained by present data. The characteristic features of
this scenario for the relevant decay rates and distributions are investigated.
We emphasize that both sign and magnitude of the forward-backward asymmetry of
the decay leptons in , , carry sensitive information on New Physics. The observable is proposed as a useful probe of
non-standard CP violation in couplings.Comment: Minor modifications; version to appear in Phys. Rev.
b -> s gamma in the left-right supersymmetric model
The rare decay is studied in the left-right supersymmetric
model. We give explicit expressions for all the amplitudes associated with the
supersymmetric contributions coming from gluinos, charginos and neutralinos in
the model to one-loop level. The branching ratio is enhanced significantly
compared to the standard model and minimal supersymmetric standard model values
by contributions from the right-handed gaugino and squark sector. We give
numerical results coming from the leading order contributions. If the only
source of flavor violation comes from the CKM matrix, we constrain the scalar
fermion-gaugino sector. If intergenerational mixings are allowed in the squark
mass matrix, we constrain such supersymmetric sources of flavor violation. The
decay sets constraints on the parameters of the model and
provides distinguishing signs from other supersymmetric scenarios.Comment: 12 figure
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