Mathematik in der PhysikOlympiade unter besonderer Berücksichtigung der Attribution

Physikwettbewerbe wie die PhysikOlympiade sollen physikinteressierte Schülerinnen und Schüler in ihrem Interesse an Physik stärken, ihre physikalischen Kompetenzen fördern und langfristig einen Beitrag zur Sicherung von genügend und gut ausgebildeten MINT-Fachkräften leisten. Wenn Teilnehmende jedoch eine negative Rückmeldung zu ihrer Leistung erhalten, zum Beispiel wenn sie schon früh im Wettbewerb ausscheiden, könnten sie dies darauf zurückführen, dass sie nicht gut genug für Physik sind. Das könnte ihrem physikalischen Selbstkonzept schaden, so dass sie sich von der Physik abwenden, womit die vom Wettbewerb angestrebten Ziele verfehlt werden könnten. Zusätzlich stellen die Aufgaben der PhysikOlympiade nicht nur physikalische, sondern auch mathematische Anforderungen an die Teilnehmenden. So könnte erschwerend hinzukommen, dass die Leistung nicht aufgrund der Physik, sondern wegen der benötigten Mathematik nicht gut genug war. Ob die mathematischen Anforderungen tatsächlich ein Problem im Physikwettbewerb sein können, worauf die Teilnehmenden ihr Abschneiden im Wettbewerb zurückführen und welche Auswirkungen dies auf ihr Selbstkonzept hat, wird in der vorliegenden Arbeit am Beispiel der PhysikOlympiade untersucht. Dazu werden zunächst Musterlösungen daraufhin analysiert, welche mathematischen Anforderungen sie umfassen. Um das Anforderungsniveau einordnen zu können, werden in einer anschließenden Studie die identifizierten mathematischen Anforderungen mit gymnasialen Mathematiklehrplänen aus vier Bundesländern abgeglichen. Die Lehrpläne dienen als Indikator, in welchem Maß die benötigte Mathematik den Wettbewerbsteilnehmenden bekannt sein dürfte oder möglicherweise Probleme bereitet. In einer dritten Studie wird untersucht, wie die Teilnehmenden ihr Ausscheiden oder die Qualifikation für die nächste Runde attribuieren und welche Zusammenhänge sich mit ihrem fachspezifischen Selbstkonzept in Physik sowie in Mathematik finden lassen.Physics competitions like the German Physics Olympiad aim at strengthening students' interest in physics, fostering their physics competencies and contributing to ensure a sufficient amount of personnel in the field of STEM. However, if participants get negative feedback on their performance, for instance by failing early in the competition, they might conclude that they are not good enough at physics. This could harm their physics self-concept and let them turn to other domains, so the competitions' goals would be missed. Additionally, to solve the tasks in the German Physics Olympiad, both physics and mathematics knowledge is needed. So, students’ failure could be due to a lack of the physics or mathematics knowledge required. Using the German Physics Olympiad as an example, this dissertation investigates: whether mathematical requirements can indeed be a problem in physics competitions, which causes participants perceive as relevant for their competition result, and how their self-concept is affected. In a first study, sample solutions of tasks used in the German Physics Olympiad are analyzed to identify their mathematical requirements. In a second study, the identified mathematical requirements are compared to Gymnasium mathematics curricula from four federal states to estimate to what extent the participants should be expected to possess the needed mathematics knowledge. A third study examines the participants’ perception of the causes of their competitions result, i.e. qualifying or not qualifying for the next selection round (hereafter referred to as attributions). Additionally, relationships between the participants’ attributions and their physics as well as mathematics self-concept are investigated

Exercise Hypertension in Athletes

Background: An exaggerated blood pressure response (EBPR) during exercise testing is not well defined, and several blood pressure thresholds are used in different studies and recommended in different guidelines. Methods: Competitive athletes of any age without known arterial hypertension who presented for preparticipation screening were included in the present study and categorized for EBPR according to American Heart Association (AHA), European Society of Cardiology (ESC), and American College of Sports Medicine (ACSM) guidelines as well as the systolic blood pressure/MET slope method. Results: Overall, 1137 athletes (mean age 21 years; 34.7% females) without known arterial hypertension were included April 2020–October 2021. Among them, 19.6%, 15.0%, and 6.8% were diagnosed EBPR according to ESC, AHA, and ACSM guidelines, respectively. Left ventricular hypertrophy (LVH) was detected in 20.5% of the athletes and was approximately two-fold more frequent in athletes with EBPR than in those without. While EBPR according to AHA (OR 2.35 [95%CI 1.66–3.33], p p = 0.031) was independently (of age and sex) associated with LVH, EBPR defined according to ESC guidelines (OR 1.49 [95%CI 1.00–2.23], p = 0.051) was not. In adult athletes, only AHA guidelines (OR 1.96 [95%CI 1.32–2.90], p = 0.001) and systolic blood pressure/MET slope method (OR 1.73 [95%CI 1.08–2.78], p = 0.023) were independently predictive for LVH. Conclusions: Diverging guidelines exist for the screening regarding EBPR. In competitive athletes, the prevalence of EBPR was highest when applying the ESC (19.6%) and lowest using the ACSM guidelines (6.8%). An association of EBPR with LVH in adult athletes, independently of age and sex, was only found when the AHA guideline or the systolic blood pressure/MET slope method was applied

Impurity states in the magnetic topological insulator V:(Bi,Sb)2Te3\mathrm{V:(Bi,Sb)_{2}Te_{3}}

The ferromagnetic topological insulatorV:(Bi,Sb)$_{2}$Te$_{3}$ has been recently reported as a quantum anomalous Hall (QAH) system. Yet the microscopic origins of the QAH effect and the ferromagnetism remain unclear. One key aspect is the contribution of the V atoms to the electronic structure. Here the valence band of V:(Bi,Sb)$_{2}$Te$_{3}$ thin films was probed in an element-specific way by resonant photoemission spectroscopy. The signature of the V 3d impurity band was extracted and exhibits a high density of states near the Fermi level, in agreement with spin-polarized first-principles calculations. Our results indicate the occurrence of a ferromagnetic superexchange interaction mediated by the observed impurity band, contributing to the ferromagnetism in this system