Securing of resources as a valid reason for using force? – A pre-emptive defence of the prohibition on the use of force

A growing demand for natural resources embedded in current changes of the international order will put pressure on states to secure the future availability of these resources. Some political discourses suggest that states might respond by challenging the foundations of international law. Whereas the UN Charter was inter alia aimed at eliminating uses of force for economic reasons, one may observe an on-going trend of securitization of matters of resource supply resulting into the revival of self-preservation doctrines. The chapter will show that those claims lack a normative foundation in the current framework of the prohibition of the use of force. Moreover, international law has sufficient instruments to cope with disputes over access to resources by other means than the use of force. The international community, therefore, must oppose claims that may contribute to normative uncertainties and strengthen already existing instruments of pacific settlement of disputes

Concentration Compactness for the Critical Maxwell-Klein-Gordon Equation

We prove global regularity, scattering and a priori bounds for the energy critical Maxwell-Klein-Gordon equation relative to the Coulomb gauge on (1+4)-dimensional Minkowski space. The proof is based upon a modified Bahouri-Gerard profile decomposition [1] and a concentration compactness/rigidity argument by Kenig-Merle [10], following the method developed by the first author and Schlag [20] in the context of critical wave maps.Comment: 160 pages. Minor revisions. To appear in Annals of PD

Zur Perspektive von Mentor*innen auf Schulpraktika im Fach Sport: Eine Interviewstudie zum Potenzial von Mentoring als Teil beruflichen Lernens von Sportlehrkräften

Die vorliegende Untersuchung fokussiert Schulpraktika als Anstoß beruflicher Lernprozesse von Mentor*innen. Forschungsmethodisch ist die Studie in ein forschungsorientiertes Entwicklungsprojekt eingegliedert, in dem eine Maßnahme entwickelt wurde, durch die eine verstärkte Kooperation zwischen den Dozent*innen der universitären Begleitseminare zu den Praktika und den Mentor*innen erreicht werden soll. Dies wird als phasenübergreifende Kooperation bezeichnet (Wibowo & Krieger, 2019a). Zur Evaluation der Maßnahme wurden 13 Mentor*innen aus zwei Kohorten dazu interviewt, inwiefern phasenübergreifende Kooperation in Schulpraktika als Lerngelegenheit wahrgenommen wird. Die Ergebnisse deuten darauf hin, dass das Zustandekommen von beruflichen Lernprozessen durch die organisatorische und inhaltliche Flexibilität der Maßnahme, die Konkretheit des Seminarinhalts, die Passung der Inhalte zu individuellen Überzeugungen und das Abwägen eins Gesamt-Kosten-Nutzen-Verhältnisses beeinflusst wird

Flooding prevention in distillation and extraction columns with aid of machine learning approaches

Flooding of separation columns is a severe limitation in the operation of distillation and liquid-liquid extraction columns. To observe operation conditions, machine learning algorithms are implemented to recognize the flooding behavior of separation columns on laboratory scale. Besides this, the investigated columns already provided the modular automation interface Module Type Package (MTP), which is used for data access of necessary sensor data. Hence, artificial intelligence (AI) tools with deep learning offer high potential for the process industry and allow to capture operating states that are otherwise difficult to detect or model. However, the advanced methods are only hesitantly applied in practice due to complex combination of operational sensing, data analysis, and active control of the equipment. This article provides an overview on how AI-based algorithms can be implemented in existing laboratory plants. Process sensor data as well as image data are used to model the flooding behavior of distillation and extraction columns for stable and robust operational conditions

Concentration compactness for critical radial wave maps

We consider radially symmetric, energy critical wave maps from (1 + 2)-dimensional Minkowski space into the unit sphere $\mathbf{S}^m$, m≥1, and prove global regularity and scattering for classical smooth data of finite energy. In addition, we establish a priori bounds on a suitable scattering norm of the radial wave maps and exhibit concentration compactness properties of sequences of radial wave maps with uniformly bounded energies. This extends and complements the beautiful classical work of Christodoulou-Tahvildar-Zadeh [3, 4] and Struwe [31, 33] as well as of Nahas [22] on radial wave maps in the case of the unit sphere as the target. The proof is based upon the concentration compactness/rigidity method of Kenig-Merle [6, 7] and a “twisted” Bahouri-Gérard type profile decomposition [1], following the implementation of this strategy by the second author and Schlag [17] for energy critical wave maps into the hyperbolic plane as well as by the last two authors [16] for the energy critical Maxwell-Klein-Gordon equation

Ligand binding shifts highly mobile RXR to chromatin-bound state in a coactivator-dependent manner as revealed by single cell imaging.

Retinoid X Receptor (RXR) is a promiscuous nuclear receptor forming heterodimers with several other receptors, which activate different sets of genes. Upon agonist treatment the occupancy of its genomic binding regions increased, but only a modest change in the number of sites was revealed by ChIP-Seq, suggesting a rather static behavior. However, such genome-wide and biochemical approaches do not take into account the dynamic behavior of a transcription factor. Therefore we characterized the nuclear dynamics of RXR during activation in single cells on the sub-second scale using live-cell imaging. By applying FRAP and fluorescence correlation spectroscopy (FCS), techniques with different temporal and spatial resolution, a highly dynamic behavior could be uncovered, which is best described by a two-state model of receptor mobility. In the unliganded state most RXRs belonged to the fast population, leaving approximately 15% for the slow, chromatin bound fraction. Upon agonist treatment, this ratio increased to approximately 43% as a result of an immediate and reversible redistribution. Coactivator binding appears to be indispensable for redistribution and has a major contribution to chromatin association. A nuclear mobility map recorded by light sheet microscopy-FCS shows that the ligand-induced transition from the fast to the slow population occurs throughout the nucleus. Our results support a model in which RXR has a distinct, highly dynamic nuclear behavior and follows hit-and-run kinetics upon activation

Spectroscopic perspective on the interplay between electronic and magnetic properties of magnetically doped topological insulators

We combine low energy muon spin rotation (LE-$\mu$SR) and soft-X-ray angle-resolved photoemission spectroscopy (SX-ARPES) to study the magnetic and electronic properties of magnetically doped topological insulators, (Bi,Sb)$_2$Te$_3$. We find that one achieves a full magnetic volume fraction in samples of (V/Cr)$_x$(Bi,Sb)$_{2-x}$Te$_3$ at doping levels x $\gtrsim$ 0.16. The observed magnetic transition is not sharp in temperature indicating a gradual magnetic ordering. We find that the evolution of magnetic ordering is consistent with formation of ferromagnetic islands which increase in number and/or volume with decreasing temperature. Resonant ARPES at the V $L_3$ edge reveals a nondispersing impurity band close to the Fermi level as well as V weight integrated into the host band structure. Calculations within the coherent potential approximation of the V contribution to the spectral function confirm that this impurity band is caused by V in substitutional sites. The implications of our results on the observation of the quantum anomalous Hall effect at mK temperatures are discussed

Proximity-Induced Odd-Frequency Superconductivity in a Topological Insulator

At an interface between a topological insulator (TI) and a conventional superconductor (SC), superconductivity has been predicted to change dramatically and exhibit novel correlations. In particular, the induced superconductivity by an $s$-wave SC in a TI can develop an order parameter with a $p$-wave component. Here we present experimental evidence for an unexpected proximity-induced novel superconducting state in a thin layer of the prototypical TI, Bi$_2$Se$_3$, proximity coupled to Nb. From depth-resolved magnetic field measurements below the superconducting transition temperature of Nb, we observe a local enhancement of the magnetic field in Bi$_2$Se$_3$ that exceeds the externally applied field, thus supporting the existence of an intrinsic paramagnetic Meissner effect arising from an odd-frequency superconducting state. Our experimental results are complemented by theoretical calculations supporting the appearance of such a component at the interface which extends into the TI. This state is topologically distinct from the conventional Bardeen-Cooper-Schrieffer state it originates from. To the best of our knowledge, these findings present a first observation of bulk odd-frequency superconductivity in a TI. We thus reaffirm the potential of the TI-SC interface as a versatile platform to produce novel superconducting states.Comment: Accepted version for publication in Physical Review Letter