Doppler lidars are frequently used for wind measurements in the atmospheric boundary layer, but their data are subject to spatial averaging due to the pulse length of the laser and sampling frequency of the return signal. This spatial averaging also affects estimates of turbulence statistics like the velocity variance and outer scale of turbulence from Doppler lidar data. In this study a procedure from Frehlich and Cornman based on a von Kármán turbulence model was systematically applied to correct these effects of spatial averaging on turbulence statistics. The model was able to reduce the occurring bias of the velocity variance and outer scale of turbulence in a comparison of time series from a Doppler lidar and an ultrasonic anemometer. The measurements show that the bias of the velocity variance was reduced by 29% and that of the outer scale of turbulence by 43%. But both turbulence parameters had a remaining systematic error that could not be explained by the von Kármán model of the structure function.
Background
Unprecedented numbers of migrants have arrived in Europe, including children and adolescents. Little is known about their unique health needs. Prospective data collection has been sparse. Mobile applications may help to facilitate global health surveillance.
Methods
A pre-validated survey instrument was converted into a mobile application covering self-reported exposures and disruptions of healthcare before/during migration, communicable and non-communicable diseases. Participation was voluntary, anonymous and confidential.
Results
Data were obtained from 405 migrant children and adolescents in Berlin, Germany, between 7 October 2015 and 15 March 2016 (median age 19 years, range: 1–24; 80.7% males) with the majority from Syria (62.5%), Afghanistan (9.1%) and Iraq (8.2%). In total, 55% were without family, 64% registered asylum-seekers with access to healthcare; 54% had seen a doctor since arrival, with colds or respiratory complaints (37.5 and 13.6%), followed by pain (26.7%) gastrointestinal (12.4%) and skin problems (11.1%). Underlying conditions were reported in 15.6%, predominantly asthma. Overall, 73% reported being up-to date on immunizations, but only 22% held a vaccination record with 46.4% having lost it during migration.
Conclusions
The lack of medical and immunization records among newly arrived migrants provides a challenge to healthcare systems. Mobile applications offer rapid screening tools in times of crisis, helping stakeholders with timely information.
Up to now informative studies have not reliably shown that the effect of ambulatory health education programmes for overweight and obese children and adolescents and their parents may last for more than one or two years. Therefore, a controlled clinical trial determining the long-term effectiveness of such programme is imperative. The decision whether a defined programmes should be included in such a study could be taken on the basis of the quality indicators and assessment criteria described here.
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