The normal mapping technique is widely used in computer graphics to visualize three-dimensional (3D) objects displayed on a flat screen. Taking advantage of optical properties of metasurfaces, which provide a highly efficient approach for manipulation of incident light wavefront, we have designed a metasurface to implement diffuse reflection and used the concept of normal mapping to control its scattering properties. As a proof of principle, we have fabricated and characterized a flat diffuse metasurface imitating lighting and shading effects of a 3D cube. The 3D image is displayed directly on the illuminated metasurface and it is brighter than a standard white paper by up to 2.4 times. The designed structure performs equally well under coherent and incoherent illumination. The normal mapping approach based on metasurfaces can complement traditional optical engineering methods of surface profiling and gradient refractive index engineering in the design of 3D security features, high-performance planar optical diffusers, novel optical elements, and displays.
The aim of this study was to investigate inter-day and-week as well as intra-and interindividual variation of selected biomarkers in high-performance youth soccer players to assist practitioners interpreting player's internal load to counteract underperformance and unwanted health risks. Eleven male youth soccer players were tested multiple times during two 3-week periods at midpoint (3-wk mid) and at the end (3-wk end) of the first half of a German under-19 1. Bundesliga season. The levels of creatine kinase (CK), urea, and C-reactive protein (CRP) were measured during 3-wk mid and 3-wk end each Monday, Wednesday, and Friday. In 3-wk mid the CK median was 14% higher (241 vs. 212 U/L) compared to 3-wk end (P = 0.26, ES = 0.16). Overall, the medians of CK, urea (P = 0.59, ES = 0.08), and CRP (P = 0.56, ES = 0.10) during 3-wk mid did not differ to the values of 3-wk end. Daily coefficient of variations (CVs) ranged from 22 to 71% (CK), 17 to 37% (urea), and 9 to 164% (CRP). Individual medians ranged from 101 to 350 U/L (CK), 23 to 50 mg/dL (urea), and 0.6 to 1.1 mg/L (CRP). High intra-individual variability was demonstrated by large intra-individual CVs (medians: CK 50%, urea 18%, and CRP 45%). Our data show (i) large inter-day and inter-week variability of all biomarkers, depending on the external load and (ii) considerable inter-and intra-individual parameter variations. Creatine kinase concentrations could sensitively reflect soccer-specific loads during the season.
Als im Kontext der COVID-19-Pandemie das öffentliche Leben massiv eingeschränkt wurde, sah sich auch das Hochschulwesen mit ganz neuen Anforderungen konfrontiert. Im März 2020 zeichnete sich ab, dass das Sommersemester unter keinen Umständen im "Normalbetrieb" ablaufen würde, wobei die Reaktionen zunächst zögerlich waren: Inmitten einer dynamischen und präzedenzlosen Lage konnten die Universitätsleitungen den Lehrenden nur langsam und schrittweise mitteilen, unter welchen Bedingungen-und ab wann-im Sommersemester unterrichtet werden sollte. Ressourcen sowie Potenziale des eLearning mussten recht zügig abgewogen und Werkzeuge für innovative krisenresistente Lehrszenarien gefunden werden. Schnelles Handeln in der Umstellung von Präsenz-zu Online-Lehre war also gefragt, um "eine Gratwanderung zwischen schneller Reaktion und Qualität zu meistern" (Tovar 2020). Der Technologieeinsatz stellte im hochschuldidaktischen Bildungsprozess plötzlich ein unverzichtbares Element dar, und vorhandene Präsenzlehrkonzepte mussten über Nacht digitalisiert werden. Über Jahre eingespielte Prozesse griffen plötzlich nicht mehr: Fest geplante Seminare, Vorlesungen und Übungen wurden angepasst und "umgemodelt", und obwohl die Universitätsleitungen auf Hochtouren an technischen Infrastrukturen für eine kontaktlose Lehre arbeiteten, existierte lange kein klarer Fahrplan für den Corona-Sommer. Dementsprechend wurden dezentral sehr unterschiedliche Lehrmodelle-synchron, asynchron oder blended, Video-, Podcast-oder textbasiert,-in Erwägung gezogen,
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