Research governance in placebo-controlled trials: Is the EMA/ICH position consistent in itself and in accordance with the declaration of helsinki?

The European Medicines Agency and the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use are powerful international institutions for the regulation of biomedical research. Although not directly concerned with the ethical aspects of research, both institutions have disseminated position papers on ethical issues relating to the use of placebos in clinical trials. What appears initially to be guidance on the methodology of placebo-controlled trials (with very technical content) clearly has some far-reaching implications for the extent of risk patients can be expected to be subjected to in such trials. On the basis of this guidance, this article questions how much additional harm to patients would be acceptable in placebo-controlled trials in comparison with active-control trials. The article will show that the instruments provided in the guidance are unsuitable, remaining unclear on vital points and thereby leaving patients, researchers and research ethics committees without appropriate direction. In conclusion, placebo-controlled trials urgently need more. © The Author(s) 2014

Advertisement-financed credit ratings

This paper investigates the incentives of a credit rating agency (CRA) to generate accurate ratings under an advertisement-based business model. To this end, we study a two-period endogenous reputation model in which a CRA can increase the precision of its ratings by exerting effort. The CRA receives a revenue not from rating fees, as is standard in the literature, but through online advertising. We show that the advertisement-based business model provides sufficient incentives for the CRA to improve the precision of signals at intermediate levels of reputation. Furthermore, we identify conditions under which truthful reporting is incentive compatible. © 2021, The Author(s)

Suitability of Transport Techniques for Video Transmission in IP Networks

The paper discusses the problem of video transmission in an IP network. The authors consider the ability of using the most popular video codecs that use both the MPEG2 Transport Stream and Dynamic Adaptive Streaming over Hypertext Transfer Protocol (DASH). The main emphasis was given to ensuring the quality of service and quality assessment methods, taking into account not only the service- or network provider’s point of view but also the end user’s perspective. Two quality assessment approaches were presented, i.e. objective and subjective methods. The authors presented the results of the quality evaluation for H.264/MPEG-4, H.265/HEVC and VP9 codecs. The objective measurements, proved by statistical analysis of user opinion scores, confirmed the ability of using H.265 and VP9 codecs in both real time and streaming transmissions, while the quality of video streaming over HTTP with the H.264 codec proved inadequate. The authors also presented a connection between the dynamics of network bandwidth changing and MPEG-DASH mechanism operation and their influence on thequality experienced by users

Möglichkeiten der Strukturierung von Hedgefondsportfolios

The year 2000 started the evolution of the German market for Structured Products with incorporated Hedge Fund exposures. This paper provides an extensive commentary on this fast growing segment. Our analysis suggests that the market for existing products is affected by significant heterogeneity. This heterogeneity relates to amongst others the underlying product and cost structure, the performance and the investment style. The diversity and flexibility that enables the investor to acquire a tailor-made and portfolio-optimized asset allocation, has proven to remain attractive, despite the events of recent years. A new investment act ('Investmentmodernisierungsgesetz') was implemented in Germany in 2004. This means that direct investments in (Fund of) Hedge Funds now compete against Structured Products. However our analysis concludes that these product groups coexist. One reason is the innovation power of financial engineers who continuously create new structured products with specific features. --Hedgefonds,Structured Products,Index Certificates,Constant Proportion Portfolio Insurance,Indizes

Heterogenität von Hedgefondsindizes

Most research on the performance and risk of hedge funds are based on calculations that just use the data from one index provider. Also most product providers and even more and more investors are using hedge fund indices for benchmarking purposes. As some academic articles pointed out, the world of hedge fund indices is very heterogeneous. So the empirical results on the optimal hedge fund allocation an investor would obtain by using the indices of one data provider could severely change if he would use another subset of indices. This paper analyses the heterogeneity of hedge fund indices that results from the fact that each index provider looks at a different subset of underlying hedge funds. Therefore we calculate different risk and return measures for the data series of six different hedge fund index providers and highlight the observed differences. In a next step, we rank the results we obtained, to find out which composite and strategy indices from which data provider are best used for benchmarking purposes from the point of view of the investor. --Heterogenität,Volatilität,Sharpe Ratio,Sterling Ratio,Calmar Ratio,Omega,Autokorrelation,Sortino Ratio,Schiefe,Wölbung,Kurtosis,Persistenz

Quantized Nambu-Poisson Manifolds and n-Lie Algebras

We investigate the geometric interpretation of quantized Nambu-Poisson structures in terms of noncommutative geometries. We describe an extension of the usual axioms of quantization in which classical Nambu-Poisson structures are translated to n-Lie algebras at quantum level. We demonstrate that this generalized procedure matches an extension of Berezin-Toeplitz quantization yielding quantized spheres, hyperboloids, and superspheres. The extended Berezin quantization of spheres is closely related to a deformation quantization of n-Lie algebras, as well as the approach based on harmonic analysis. We find an interpretation of Nambu-Heisenberg n-Lie algebras in terms of foliations of R^n by fuzzy spheres, fuzzy hyperboloids, and noncommutative hyperplanes. Some applications to the quantum geometry of branes in M-theory are also briefly discussed.Comment: 43 pages, minor corrections, presentation improved, references adde

Investigating Correlations of Automatically Extracted Multimodal Features and Lecture Video Quality

Ranking and recommendation of multimedia content such as videos is usually realized with respect to the relevance to a user query. However, for lecture videos and MOOCs (Massive Open Online Courses) it is not only required to retrieve relevant videos, but particularly to find lecture videos of high quality that facilitate learning, for instance, independent of the video's or speaker's popularity. Thus, metadata about a lecture video's quality are crucial features for learning contexts, e.g., lecture video recommendation in search as learning scenarios. In this paper, we investigate whether automatically extracted features are correlated to quality aspects of a video. A set of scholarly videos from a Mass Open Online Course (MOOC) is analyzed regarding audio, linguistic, and visual features. Furthermore, a set of cross-modal features is proposed which are derived by combining transcripts, audio, video, and slide content. A user study is conducted to investigate the correlations between the automatically collected features and human ratings of quality aspects of a lecture video. Finally, the impact of our features on the knowledge gain of the participants is discussed