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Lack of physical activity is a global public health problem causing not only morbidity and premature mortality, but it is also a major economic burden worldwide. One of the cornerstones of a physically active lifestyle is Motor Competence (MC). MC is a complex biocultural attribute and therefore, its study requires a multi-sectoral, multi-, inter- and transdisciplinary approach. MC is a growing area of research, especially in children and adolescents due to its positive association with a plethora of health and developmental outcomes. Many questions, however, remain to be answered in this field of research, with regard to: (i) Health and Developmental-related Associations of MC; (ii) Assessment of MC; (iii) Prevalence and Trends of MC; (iv) Correlates and Determinants of MC; (v) MC Interventions, and (vi) Translating MC Research into Practice and Policy. This paper presents a narrative review of the literature, summarizing current knowledge, identifying key research gaps and presenting questions for future investigation on MC in children and adolescents. This is a collaborative effort from the International Motor Competence Network (IMCNetwork) a network of academics and researchers aiming to promote international collaborative research and knowledge translation in the expansive field of MC. The knowledge and deliverables generated by addressing and answering the aforementioned research questions on MC presented in this review have the potential to shape the ways in which researchers and practitioners promote MC and physical activity in children and adolescents across the world. © 2020 by the authors.

BACKGROUND: Despite the large number of studies and reviews available, the evidence regarding the biological determinants of physical activity (PA) is inconclusive. In this umbrella review, we summarized the current evidence on the biological determinants of PA across the life course, by pooling the results of the available systematic literature reviews (SLRs) and meta-analyses (MAs). METHODS: We conducted an online search on MEDLINE, ISI Web of Science, Scopus, and SPORTDiscus databases up to January 2018. SLRs and MAs of observational studies that investigated the association between biological determinants of PA and having PA as outcome were considered eligible. The extracted data were assessed based on the importance of the determinants, the strength of evidence, and the methodological quality. RESULTS: We identified 19 reviews of which most were of moderate methodological quality. Determinants that were studied most frequently among all ages and demonstrated evidence suggesting a positive association to PA were younger age, being male, higher health status, and higher physical fitness levels. Among adults, normal birth weight was found to be positively associated to PA with convincing strength of evidence, while findings among adolescents were inconsistent and with limited strength of evidence. CONCLUSIONS: Different social or behavioral factors may contribute to the decrease of PA with age and among females versus males, and creating programmes targeted at diverse ages, female population, and adults with abnormal birth weight is recommended. Future studies should use prospective study designs, standardized definitions of PA, and objective measurement methods of PA assessment.

BACKGROUND: Despite the large number of studies and reviews available, the evidence regarding the policy determinants of physical activity (PA) is inconclusive. This umbrella systematic literature review (SLR) summarizes the current evidence on the policy determinants of PA across the life course, by pooling the results of the available SLRs and meta-analyses (MAs). METHODS: A systematic online search was conducted on MEDLINE, ISI Web of Science, Scopus and SPORTDiscus databases up to April 2016. SLRs and MAs of observational studies investigating the association between policy determinants of PA and having PA as outcome were considered eligible. The extracted data were assessed based on the importance of the determinants, the strength of evidence and the methodological quality. RESULTS: Fourteen reviews on 27 policy determinants of PA were eligible for this umbrella SLR. The majority of the reviews were of moderate quality. Among children, a clear association between time spent outdoors and PA emerged. Among adults, working hours were negatively associated with PA, though evidence was limited. At the population level, community- and street-scale urban design and land use policies were found to positively support PA levels, but levels of evidences were low. CONCLUSIONS: With this umbrella SLR the policy determinants of PA at individual-level and Population-level have been summarized and assessed. None of the investigated policy determinants had a convincing level of evidence, and very few had a probable level of evidence. Further research is needed, preferably by using prospective study designs, standardized definitions of PA and objective measurement of PA.

BACKGROUND: To date, the scientific literature on socioeconomic correlates and determinants of physical activity behaviours has been dispersed throughout a number of systematic reviews, often focusing on one factor (e.g. education or parental income) in one specific age group (e.g. pre-school children or adults). The aim of this umbrella review is to provide a comprehensive and systematic overview of the scientific literature from previously conducted research by summarising and synthesising the importance and strength of the evidence related to socioeconomic correlates and determinants of PA behaviours across the life course. METHODS: Medline, Embase, ISI Web of Science, Scopus and SPORTDiscus were searched for systematic literature reviews and meta-analyses of observational studies investigating the association between socioeconomic determinants of PA and PA itself (from January 2004 to September 2017). Data extraction evaluated the importance of determinants, strength of evidence, and methodological quality of the selected papers. The full protocol is available from PROSPERO (PROSPERO2014:CRD42015010616). RESULTS: Nineteen reviews were included. Moderate methodological quality emerged. For adults, convincing evidence supports a relationship between PA and socioeconomic status (SES), especially in relation to leisure time (positive relationship) and occupational PA (negative relationship). Conversely, no association between PA and SES or parental SES was found for pre-school, school-aged children and adolescents. CONCLUSIONS: Available evidence on the socioeconomic determinants of PA behaviour across the life course is probable (shows fairly consistent associations) at best. While some evidence is available for adults, less was available for youth. This is mainly due to a limited quantity of primary studies, weak research designs and lack of accuracy in the PA and SES assessment methods employed. Further PA domain specific studies using longitudinal design and clear measures of SES and PA assessment are required.

OBJECTIVE: Regular physical activity (PA) reduces the risk of disease and premature death. Knowing factors associated with PA might help reducing the disease and economic burden caused by low activity. Studies suggest that socio-cultural factors may affect PA, but systematic overviews of findings across the life course are scarce. This umbrella systematic literature review (SLR) summarizes and evaluates available evidence on socio-cultural determinants of PA in children, adolescents, and adults. METHODS: This manuscript was drafted following the recommendations of the 'Preferred Reporting Items for Systematic reviews and Meta-Analyses' (PRISMA) checklist. The MEDLINE, Web of Science, Scopus, and SPORTDiscus databases were searched for SLRs and meta-analyses (MAs) on observational studies published in English that assessed PA determinants between January 2004 and April 2016. The methodological quality was assessed and relevant information on socio-cultural determinants and any associations with PA was extracted. The available evidence was evaluated based on the importance of potential determinants and the strength of the evidence. RESULTS: Twenty SLRs and three MAs encompassing 657 eligible primary studies investigated potential socio-cultural PA determinants, with predominantly moderate methodological quality. Twenty-nine potential PA determinants were identified that were primarily assessed in children and adolescents and investigated the micro-environmental home/household level. We found probable evidence that receiving encouragement from significant others and having a companion for PA were associated with higher PA in children and adolescents, and that parental marital status (living with partner) and experiencing parental modeling were not associated with PA in children. Evidence for the other potential determinants was limited, suggestive, or non-conclusive. In adults, quantitative and conclusive data were scarce. CONCLUSIONS: A substantial number of SLRs and MAs investigating potential socio-cultural determinants of PA were identified. Our data suggest that receiving social support from significant others may increase PA levels in children and adolescents, whereas parental marital status is not a determinant in children. Evidence for other potential determinants was limited. This was mainly due to inconsistencies in results on potential socio-cultural determinants of PA across reviews and studies. TRIAL REGISTRATIONS: This umbrella SLR was recorded on PROSPERO (Record ID: CRD42015010616).

Low levels of physical activity (PA) are reported to contribute to the occurrence of non-communicable diseases over the life course. Although psychological factors have been identified as an important category concerning PA behavior, knowledge on psychological determinants of PA is still inconclusive. Therefore, the aim of this umbrella systematic literature review (SLR) was to summarize and synthesize the scientific evidence on psychological determinants of PA behavior across the life course. A systematic online search was conducted on MEDLINE, ISI Web of Science, Scopus, and SPORTDiscus databases. The search was limited to studies published in English from January 2004 to April 2016. SLRs and meta-analyses (MAs) of observational studies investigating the association of psychological variables and PA were considered eligible. Extracted data were evaluated based on importance of determinants, strength of evidence, and methodological quality. The full protocol is available from PROSPERO (Record ID: CRD42015010616). Twenty reviews (14 SLRs and 6 MAs), mostly of moderate methodological quality, were found eligible. Convincing evidence was found for self-efficacy (positive association with PA) in children and adolescents, and stress (negative association with PA) regardless of age. Most of the evidence revealing an association between psychological determinants and PA is probable and limited, mainly due to differences in the definition of PA and of psychological determinants across reviews. Thus, scholars are urged to reach a consensus on clear definitions of relevant psychological determinants of PA, subsuming cultural biases and allowing the possibility to obtain clear interpretations and generalizability of findings. Finally, most psychological determinants should be considered within a larger framework of other multi-level determinants that may interact or mediate some of the effects.

Background: Participation in regular physical activity is associated with a multitude of health benefits across the life course. However, many people fail to meet PA recommendations. Despite a plethora of studies, the evidence regarding the environmental (physical) determinants of physical activity remains inconclusive. Objective: To identify the physical environmental determinants that influence PA across the life course. Methods: An online systematic literature search was conducted using MEDLINE, ISI Web of Science, Scopus and SPORTDiscus. The search was limited to studies published in English (January 2004 to April 2016). Only systematic literature reviews (SLRs) and meta-analyses (MAs) of observational studies, that investigated the association between physical determinants and physical activity outcomes, were eligible for inclusion. The extracted data were assessed on the importance of determinants, strength of evidence and methodological quality. Results: The literature search identified 28 SLRs and 3 MAs on 67 physical environmental characteristics potentially related to physical activity that were eligible for inclusion. Among preschool children, a positive association was reported between availability of backyard space and outdoor toys/equipment in the home and overall physical activity. The availability of physical activity programs and equipment within schools, and neighbourhood features such as pedestrian and cyclist safety structure were positively associated with physical activity in children and adolescents. Negative street characteristics, for example, lack of sidewalks and streetlights, were negatively associated with physical activity in adults. Inconsistent associations were reported for the majority of reviewed determinants in adults. Conclusion: This umbrella SLR provided a comprehensive overview of the physical environment determinants of physical activity across the life course and has highlighted, particularly amongst youth, a number of key determinants that may be associated with overall physical activity. Given the limited evidence drawn mostly from cross-sectional studies, longitudinal studies are needed to further explore these associations. Registration: PROSPERO CRD42015010616.

BACKGROUND: Low levels of physical activity (PA) are a global concern and increasing PA engagement is becoming a priority in current public health policies. Despite the large number of studies and reviews available, the evidence regarding the behavioral determinants of PA is still inconclusive. Thus, the aim of this umbrella systematic literature review (SLR) was to summarize the evidence on the behavioral determinants of PA across the life course. METHODS: A systematic online search was conducted on MEDLINE, ISI Web of Science, Scopus, and SPORTDiscus databases. The search was limited to studies published in English from January, 2004 to April, 2016. SLRs and meta-analyses (MAs) of observational studies that investigated the behavioral determinants of PA were considered eligible. The extracted data were assessed based on the importance of the determinants, the strength of evidence, and the methodological quality. The full protocol is available from PROSPERO (PROSPERO 2014:CRD42015010616). RESULTS: Seventeen reviews on 35 behavioral determinants of PA were eligible for this umbrella SLR. Regardless of age, the most investigated determinants were those related with 'screen use' and 'smoking'. For youth, probable positive evidence emerged for 'previous PA' and 'independent mobility and active transport' among children and adolescents. For the adult population, 'transition to university' and 'pregnancy/having a child' showed probable negative associations. CONCLUSIONS: Although the majority of the evidence was limited and most of the determinants were not associated with PA, this umbrella SLR provided a comprehensive overview of the associations between behavioral determinants and PA. Youth should be physically active in the early years and increase active transportation to/from school, independent mobility, and 'free-range activities' without adult supervision, whilst adult PA behaviors are mostly influenced by the life events. Finally, more research is needed that incorporates prospective study designs, standardized definitions of PA, objective measurement methods of PA assessment, and the use of interactionist and mediational approaches for the evaluation of different behavioral determinants influencing PA behaviors.

National audience; L’évaluation du risque écologique des substances chimiques requiert l’utilisation de biotests, de laboratoire ou de terrain, permettant d’établir une relation directe entre la présence de contaminants et leur toxicité dans les milieux. Cette étape est une condition essentielle pour la mise en oeuvre de programmes pertinents pour la restauration des milieux aquatiques. L’expérimentation in situ, via l’encagement d’organismes calibrés issus de populations contrôles, permet de limiter l’impact de facteurs de confusion biologiques liés à la physiologie, la composition génétique ou encore l’histoire de vie et l’histoire d’exposition des individus et des populations. Cette approche expérimentale apparaît aujourd’hui comme essentielle pour améliorer le diagnostic des systèmes aquatiques. Dans ce contexte, chez Gammarus fossarum, nous avons développé une série de marqueurs, basés sur des réponses spécifiques comme la neurotoxicité avec l’acétylcholinestérase (Xuereb et al, 2009), la génotoxicité avec le test des Comètes (Lacaze et al., 2011), le métabolisme énergétique avec les enzymes digestives (Charron et al., 2013), l’osmorégulation (Issartel et al., 2010) et sur des traits de vie comme le taux d’alimentation (Coulaud et al., 2011) et la reproduction (Geffard et al., 2010). Pour chaque marqueur, des valeurs de référence intégrant la variabilité de ces réponses en regard de facteurs de confusion environnementaux (température, dureté..), ont été déterminées en laboratoire et validées sur le terrain. Ces valeurs conduisent à une interprétation précise des niveaux de ces marqueurs en termes de contamination et de toxicité des milieux étudiés. Toutefois, un diagnostic basé sur l’utilisation d’une espèce sentinelle et d’une population contrôle, se doit d’être pertinent pour les populations et les espèces proches présentes dans les milieux et ayant leur propre histoire de vie. En écotoxicologie aquatique, l’incertitude liée au diagnostic et associée à la variabilité des réponses biologiques entre espèces et populations, est un verrou fort et encore trop peu abordé qui reste aujourd’hui une question ouverte. De la même façon, la pertinence des choix méthodologiques pour l’expérimentation in situ, comme la durée d’exposition, reste peu argumentée. Le projet GAMMA a visé en partie à évaluer (1) la variabilité des réponses moléculaires (AchE, enzymes digestives) et traits de vie (alimentation taux, reproduction et osmorégulation) entre populations et espèces de gammaridés contrôles, (2) évaluer la divergence entre populations de la sensibilité de ces marqueurs vis-à-vis de la contamination et enfin (3) évaluer la pertinence de l’approche in situ, via une étude comparative d’encagement sur le terrain avec populations natives et proxy. Les résultats seront présentés et leurs implications pour l'évaluation écotoxicologique des systèmes aquatiques seront discutées.

International audience; Identification of unknown contaminant releases is crucial in the events of gas leakage, industrial accidents, safety and security concerns. For a point based release, the nature of a source is determined by fixed number of parameters, mainly its location and source strength. The identification of these parameters is addressed by using limited concentration measurements sampled by a network of receptors. This is formulated as over-determined linear inverse problem. To address this, an optimally weighted least-squares inversion technique is presented here. The inversion technique provides a minimum weighted norm solution and does not require initial guesses for the release parameters. This study proposes the optimality conditions under which a point source is identifiable. The inversion technique and optimality criteria are evaluated using field measurements of a single release trial# 7 conducted during Fusion Field Trials in September 2007. The point source is reconstructed within 3 m from the true release. The source strength is retrieved within a factor of 1.25 to true release mass. The optimality criteria show that the accuracy of reconstruction depends on the nature of model resolution, predictability of measurements and visibility of the true source from the receptors.

International audience; Ecological hazard assessment of chemicals for aquatic ecosystems requires the use of biological assays in order to establish relationships between contamination and effect existing in the field. This step is an essential condition for the implementation of programs meant the restoration of aquatic environments. Therefore the in situ experimentations based on the use of calibrated organisms from one control population seeking to limit biological confounding factors, appears today as essential to improve the diagnosis of aquatic systems. In this context, we developed a suite of markers addressing neurotoxicity (acetylcholinesterase), genotoxicity (Comet assay), digestive enzymes, feeding rate and reproduction impairments and capacity to osmoregulate (Xuereb et al., 2009; Geffard et al., 2010; Issartel et al., 2010) in the freshwater sentinel species Gammarus fossarum. Then, for each marker, benchmark values taking into account their natural variability in relation to environmental confounding factors (temperature, alkalinity…) have been determined and validated in field experiments. These values lead to an accurate interpretation of marker levels in terms of contamination and toxicity of aquatic systems (Coulaud et al., 2011). However, the diagnosis using a sentinel species should be relevant towards the diversity of native populations and related species with their own history. Furthermore, the relevance of the population and the species chosen as surrogate test organisms is questionable. The potential divergence of life histories and sensitivities to pollutants between experimental and native populations is in fact an open question. The Project GAMMA aims to assess (1) the natural variability of molecular responses (AchE, digestive enzymes) and life-history traits (feeding rate, reproduction and osmoregulation) in relation to geographical location of control gammarid populations and species used as sources organisms for in situ tests, and (2) the divergence of the sensitivities of these markers to contaminants between populations and species. Results will be presented and their implication for ecotoxicological assessment of aquatic systems will be discussed. Funding was provided by ANR CESA (n°021 04), GAMMA, 2012-2015.

International audience; In case of dispersion of hazardous CBRN species in the atmosphere, Source Term Estimation (STE) algorithms can be employed to provide an estimation of the release parameters (localization, intensity,⋯) by making use of concentrations and meteorological measurements. These algorithms have to be fast, reliable and accurate. One of the fastest methods for solving the source estimation inverse problem is the renormalization technique. It gives a source estimate linear with respect to the observations. This estimate corresponds to a minimum weighted-norm solution which can be expressed by making use of the generalized inverse concept. In this paper, a method for an efficient computation of this inverse solution is proposed. This method is illustrated using continuous release trials conducted during the Kitfox field experiment from September 11th to September 15th 1995, just after the 52 well known releases of August 1995. From the author's knowledge, these smooth desert experiments have never been used for validation purposes and thus can be considerate as a new data set.

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International audience; Osmoregulation represents a reliable indicator of the physiological state of crustaceans. It is mainly effected in gills via Na+/K+-ATPase (NKA) providing the major driving force for ion transport. In the present study conducted in the freshwater amphipod Gammarus fossarum, the impact of an exposure to 15 lg Cd L1 for 3 and 7 d was investigated on the haemolymph osmolality (HO), gill structure, NKA localization in gills and its relative expression. In Cd-exposed G. fossarum, mean HO significantly decreased compared to controls. In animals exposed for 3 and 7 d, high inter-individual variations in HO values were noted, resulting in their separation into unimpacted, slightly impacted and impacted animals. In unimpacted individuals, gills retained their organization, showing a thicker gill epithelium than in controls; NKA fluorescence was continuously observed along the gill epithelium and was distributed on a broader area than in controls. In slightly impacted individuals, a thinner epithelium, a slight collapse of the gill and a lower NKA fluorescence were observed compared to unimpacted specimens. In impacted individuals, dramatic alterations of the gill structure, including hyperplasia and alteration of the pillars, resulting in the collapse of the gill and the disappearance of the haemolymphatic canals were observed, as well as very limited NKA fluorescence. Therefore, the degree of gill alteration and the intensity of NKA fluorescence observed in the different groups were correlated with their respective HO levels. The relative amount of the NKA a-subunit mRNA significantly increased in specimens exposed to Cd for 3 d compared to controls, and then returned to control level after 7 d. The relationships between the changes in HO values, NKA immunostaining and mRNA relative expression are discussed. These results confirm that HO represents a valuable biomarker to evaluate crustacean health, and they underline the interest to assess individual responses to contaminants.

International audience; The measurement of atmospheric concentrations by a monitoring network is a promising tool for the identification of the widespread sources of trace species. The paper addresses the case of the species scattered linearly by a known meteorology. The question is classical: what can be said about the source from a set of measurements? Is it possible to guess from the values observed by the measurements that the source is spread close to the detectors, or that the tracer comes from a remote region? And, if the source was a point source, would it be possible to understand it by just considering these values? A part of the answers is a matter of practical sense: the resolution with which an emission can be retrieved will always be limited and probably lower for a remote region, even if the detectors and dispersion model are error free. The paper proposes a linear strategy of inference: to any set of values taken by the observed concentrations is associated linearly an estimate of the source. Doubled values lead to a doubled estimate. The method, based on adjoint techniques, is intended to optimise the resolution by quantifying, with the concept of illumination, which regions are well, poorly or not seen at all. The illumination tied to ordinary adjoint functions becomes excessive close to the detectors thus leading to inversion artefacts. This may be corrected by attributing each point of the space time domain a geometric and statistical weight. The adjoint functions are transformed. The choice of this renormalising function is constrained by an unambiguous entropic criterion preventing any overestimation of the available information that would lead to artefacts. It amounts to evenly distribute the information between the points organised with their weights as a "known domain". The theory is illustrated by calculations performed with the experimental source ETEX1.

International audience; An international monitoring system is being built as a verification tool for the Comprehensive Test Ban Treaty. Forty stations will measure on a worldwide daily basis the concentration of radioactive noble gases. The paper introduces, by handling preliminary real data, a new approach of backtracking for the identification of sources of passive tracers after positive measurements. When several measurements are available the ambiguity about possible sources is reduced significantly. The approach is validated against ETEX data. A distinction is made between adjoint and inverse transport shown to be, indeed, different though equivalent ideas. As an interesting side result it is shown that, in the passive tracer dispersion equation, the diffusion stemming from a time symmetric turbulence is necessarily a self-adjoint operator, a result easily verified for the usual gradient closure, but more general.