439 research outputs found
Health-related motor testing of children in primary school: A systematic review of criterion-referenced standards
Being physically fit in younger years prevents several diseases in the presence as well as in the life course. Therefore, monitoring physical fitness and motor competence through motor testing is essential for determining developmental status and identifying health-related risks. The main objectives of this systematic review were (1) to identify currently available health-related criterion-referenced standards and cut-off points for physical fitness and motor competence test items, (2) to frame the methodological background on setting health-related criterion-referenced standards and (3) to give implications for a health-related evaluation system for physical fitness and motor competence tests. The electronic data base search (PubMed, Web of Science and SURF) yielded 2062 records in total and identified six empirical studies reporting cut-off points of motor test items for children (7–10 years), as well as 30 methodological papers discussing determination approaches to health-related criterion-referenced standards. Data collection, selection and analyses followed the PRISMA guidelines. Health-related motor test standards need to be gender- and age-specific but should refer to an absolute cut-off point rather than to relative performance in the reference group. Due to the lack of data on health-related criterion referenced standards, receiver-operating-characteristic (ROC) curves provide a tool for the determination of cut-off points and criterion referenced standards for physical fitness and motor competence tests. A standardized approach forms the fundamental base for a globally applicable evaluation of health-related fitness tests
Influence of socioeconomic variables on physical activity and screen time of children and adolescents during the COVID‑19 lockdown in Germany: the MoMo study [Einfluss sozioökonomischer Variablen auf die körperlich-sportliche Aktivität und Bildschirmmediennutzung von Kindern und Jugendlichen während des COVID‑19-Lockdowns in Deutschland: die MoMo-Studie]
The COVID‑19 (coronavirus disease 2019) pandemic created a multitude of natural experiments about the change of human behavior in a widely unfamiliar situation. Besides physical and mental health, physical activity (PA) and people’s movement behaviors were of particular interest to researchers all over the world. In a recent study, we found that among youth in Germany, sports activity declined, whereas recreational screen time and habitual activity increased during the first COVID‑19 lockdown. In the present study, we analyze the influence of the socioeconomic status and the housing situation on the changes in PA behavior and recreational screen-time before and during the first COVID‑19 lockdown among children and adolescents living in Germany. We found an alignment of PA behavior among youth from families with different socioeconomic backgrounds during the first lockdown and identified the housing situation to be a meaningful predictor of the increase in habitual activity. We conclude that restriction policies, communities, and in the last instance parents need to enable access to nonorganized PA to all children and adolescents every day and especially during potential future lockdowns
Indicators to assess physical health of children and adolescents in activity research—A scoping review
Sufficient physical activity can help promote and maintain health, while its lack can jeopardize it. Since health and physical activity lay their foundation for later life in childhood and adolescence, it is important to examine this relationship from the beginning. Therefore, this scoping review aims to provide an overview of physical health indicators in children and adolescents in research on the effects of physical activity and sedentary behavior. We identified the indicators used to quantify or assess physical health and summarized the methods used to measure these indicators. We systematically searched Scopus, Pubmed, and Web of Science databases for systematic reviews. The search yielded 4595 records from which 32 records were included in the review. The measurements for physical health reported in the reviews contained measures of body composition, cardiometabolic biomarkers, physical fitness, harm/injury, or bone health. Body composition was the most used indicator to assess and evaluate physical health in children, whereas information on harm and injury was barely available. In future research longitudinal studies are mandatory to focus on the prospective relationships between physical activity or sedentary behavior, and physical health
A new model for magnetoreception
Certain migratory birds can sense the earth's magnetic field. The nature of
this process is not yet properly understood. Here we offer a simple explanation
according to which birds literally `see' the local magnetic field: Our model
relates the well-established radical pair hypothesis to the phenomenon of
Haidinger's brush, a capacity to see the polarisation of light. This new
picture explains recent surprising experimental data indicating long lifetimes
for the radical pair. Moreover there is a clear evolutionary path toward this
field sensing mechanism: it is an enhancement of a weak effect that may be
present in many species.Comment: 8 pages, 5 figures, version of final published pape
NEAT-FT: the European fiber link collaboration
The development of clocks based on optical transitions during the past three decades culminates in the availability of optical clocks with unprecedented stability and uncertainty . Simultaneously, increasing requirements for accurate time and frequency signals, e.g. for tests of fundamental physics or novel applications in relativistic geodesy, put forward new challenges. Typically, such applications rely on the comparison of two remote clocks. Thus, major challenges are how to synchronize these clocks over long distances or how to get the time or frequency signal of a clock to the location where it is required. It is generally agreed that optical fiber links are an excellent alternative to established satellite based distant clock comparison and synchronization techniques. A European joint research project called Network for European Accurate Time and Frequency Transfer (NEAT-FT) has been initiated in 2011 to lay the foundations for a novel approach to disseminate high-precision timing and ultrastable frequency signals by using existing fiber infrastructure. Since Europe has a large number of modern ultra-precise clocks, special emphasis is put on the development of new techniques for time transfer and phase-coherent comparison of remotely located optical clocks and the feasibility of a European fibre network connecting optical clocks in Europe. This talk highlights recent achievements and discusses some applications and prospects
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