Liquiditätsdynamik am deutschen Aktienmarkt

Die vorliegende Arbeit beschÄaftigt sich mit der LiquiditÄat am deutschen Aktienmarkt. Konkret analysieren wir den Preiseinfluss von Transaktionen. Zunächst zeigen wir in einem einfachen dynamischen Optimierungsmodell, wie die optimale Handelsstrategie eines Anlegers von der funktionalen Form der Preiseinflussfunktion abhängt. Anschließend bestimmen wir diese unter Verwendung von Orderbuchdaten aus dem XETRA-Handel. Wir finden, dass die Annahme eines in der Ordergröße linearen Preiseinflusses, wie sie in der Literatur üblicherweise verwendet wird, empirisch nicht zu halten ist. In etwa der Hälfte der Fälle ist die Preiseinflussfunktion konvex, in der anderen Hälfe der Fälle konkav. Die Form der Preiseinflussfunktion ändert sich dabei nicht rein zufällig, sondern lässt sich mit einem VAR(1)-Modell gut prognostizieren. Mit einem linearen Modell ist die Prognosegüte deutlich geringer. Die Ergebnisse unserer Studien implizieren, dass Anleger durch eine Anpassung ihrer Handelsstrategie an die Liquiditätsdynamik einen beträchtlichen Teil der liquiditätsbedingten Transaktionskosten im deutschen Aktienmarkt einsparen können.In this paper we investigate the price impact at the German Stock Exchange. In a simple dynamic model we show how the optimal trading strategy of an investor crucially depends on the functional form of the price impact function. Furthermore we determine the price impact function from order book data from the XETRA Automated Exchange. We find strong deviations of the price impact function from linearity, with it being convex for about 50% of the cases, and concave for the other 50%. Changes over time in the functional form can be predicted quite accurately by a VAR(1)-model for the parameters of a nonlinear model. In terms of forecast accuracy, a nonlinear model is superior to a linear model. The results imply that investors can reduce price impact costs at the German Stock Exchange by adjusting their trading strategies to the liquidity dynamics

Quasi-simultaneous magnetic particle imaging and navigation of nanomag/synomag-D particles in bifurcation flow experiments

Magnetic Particle Imaging (MPI) is used to visualize the distribution of superparamagnetic nanoparticles within 3D volumes with high sensitivity in real time. Recently, MPI is utilized to navigate micron-sized particles and micron-sized swimmers, since the magnetic field topology of the MPI scanner is well suited to apply magnetic forces. In this work, we analyze the magnetic mobility and imaging performance of nanomag/synomag-D for Magnetic Particle Imaging/Navigation (MPIN). With MPIN the focus fields are constantly switching between imaging and magnetic force mode, thus enabling quasi-simultaneous navigation and imaging of particles. In flow bifurcation experiment with a 100 % stenosis on one branch, we determine the limiting flow velocity of 1.36 mL/s, which allows all particles to flow only through one branch towards the stenosis. During this experiment, we image the accumulation of the particles within the stenosis. In combination with therapeutic substances, this approach has high potential for targeted drug delivery.Deutsche Forschungsgemeinschaft (DFG)Bundesministerium für Bildung und Forschung (BMBF

Comprehensive genotyping and clinical characterisation reveal 27 novel NKX2-1 mutations and expand the phenotypic spectrum

BACKGROUND: NKX2-1 encodes a transcription factor with large impact on the development of brain, lung and thyroid. Germline mutations of NKX2-1 can lead to dysfunction and malformations of these organs. Starting from the largest coherent collection of patients with a suspected phenotype to date, we systematically evaluated frequency, quality and spectrum of phenotypic consequences of NKX2-1 mutations. METHODS: After identifying mutations by Sanger sequencing and array CGH, we comprehensively reanalysed the phenotype of affected patients and their relatives. We employed electrophoretic mobility shift assay (EMSA) to detect alterations of NKX2-1 DNA binding. Gene expression was monitored by means of in situ hybridisation and compared with the expression level of MBIP, a candidate gene presumably involved in the disorders and closely located in close genomic proximity to NKX2-1. RESULTS: Within 101 index patients, we detected 17 point mutations and 10 deletions. Neurological symptoms were the most consistent finding (100%), followed by lung affection (78%) and thyroidal dysfunction (75%). Novel symptoms associated with NKX2-1 mutations comprise abnormal height, bouts of fever and cardiac septum defects. In contrast to previous reports, our data suggest that missense mutations in the homeodomain of NKX2-1 not necessarily modify its DNA binding capacity and that this specific type of mutations may be associated with mild pulmonary phenotypes such as asthma. Two deletions did not include NKX2-1, but MBIP, whose expression spatially and temporarily coincides with NKX2-1 in early murine development. CONCLUSIONS: The high incidence of NKX2-1 mutations strongly recommends the routine screen for mutations in patients with corresponding symptoms. However, this analysis should not be confined to the exonic sequence alone, but should take advantage of affordable NGS technology to expand the target to adjacent regulatory sequences and the NKX2-1 interactome in order to maximise the yield of this diagnostic effort

The Performance of Actively and Passively Managed Swiss Equity Funds

58 29) is a doctoral candidate at the University of St.Gallen and works for Wegelin & Co. Private Bankers. The authors are grateful to Hanspeter Wohlwend, Vadim Safranov, Jan Mart in Rous, Sven Wiedmer, the participants of the “Topics in Finance”-seminar at the University of St.Gallen, and the anonymous referees for their valuable comments