A Shift-Invariant Latent Variable Model for Automatic Music Transcription

In this work, a probabilistic model for multiple-instrument automatic music transcription is proposed. The model extends the shift-invariant probabilistic latent component analysis method, which is used for spectrogram factorization. Proposed extensions support the use of multiple spectral templates per pitch and per instrument source, as well as a time-varying pitch contribution for each source. Thus, this method can effectively be used for multiple-instrument automatic transcription. In addition, the shift-invariant aspect of the method can be exploited for detecting tuning changes and frequency modulations, as well as for visualizing pitch content. For note tracking and smoothing, pitch-wise hidden Markov models are used. For training, pitch templates from eight orchestral instruments were extracted, covering their complete note range. The transcription system was tested on multiple-instrument polyphonic recordings from the RWC database, a Disklavier data set, and the MIREX 2007 multi-F0 data set. Results demonstrate that the proposed method outperforms leading approaches from the transcription literature, using several error metrics

Concentration Dependence of the Effective Mass of He-3 Atoms in He-3/He-4 Mixtures

Recent measurements by Yorozu et al. (S. Yorozu, H. Fukuyama, and H. Ishimoto, Phys. Rev. B 48, 9660 (1993)) as well as by Simons and Mueller (R. Simons and R. M. Mueller, Czhechoslowak Journal of Physics Suppl. 46, 201 (1976)) have determined the effective mass of He-3 atoms in a He-3/He-4 mixture with great accuracy. We here report theoretical calculations for the dependence of that effective mass on the He-3 concentration. Using correlated basis functions perturbation theory to infinite order to compute effective interactions in the appropriate channels, we obtain good agreement between theory and experiment.Comment: 4 pages, 1 figur

Single Particle and Fermi Liquid Properties of He-3/--He-4 Mixtures: A Microscopic Analysis

We calculate microscopically the properties of the dilute He-3 component in a He-3/--He-4 mixture. These depend on both, the dominant interaction between the impurity atom and the background, and the Fermi liquid contribution due to the interaction between the constituents of the He-3 component. We first calculate the dynamic structure function of a He-3 impurity atom moving in He-3. From that we obtain the excitation spectrum and the momentum dependent effective mass. The pole strength of this excitation mode is strongly reduced from the free particle value in agreement with experiments; part of the strength is distributed over high frequency excitations. Above k > 1.7$\AA$^{-1}$ the motion of the impurity is damped due to the decay into a roton and a low energy impurity mode. Next we determine the Fermi--Liquid interaction between He-4 atoms and calculate the pressure-- and concentration dependence of the effective mass, magnetic susceptibility, and the He-3--He-3 scattering phase shifts. The calculations are based on a dynamic theory that uses, as input, effective interactions provided by the Fermi hypernetted--chain theory. The relationship between both theories is discussed. Our theoretical effective masses agree well with recent measurements by Yorozu et al. (Phys. Rev. B 48, 9660 (1993)) as well as those by R. Simons and R. M. Mueller (Czekoslowak Journal of Physics Suppl. 46, 201 (1996)), but our analysis suggests a new extrapolation to the zero-concentration limit. With that effective mass we also find a good agreement with the measured Landau parameter F_0^a.Comment: 47 pages, 15 figure

Cytotoxicity of rhein, the active metabolite of sennoside laxatives, is reduced by multidrug resistance-associated protein 1

Anthranoid laxatives, belonging to the anthraquinones as do anthracyclines, possibly increase colorectal cancer risk. Anthracyclines interfere with topoisomerase II, intercalate DNA and are substrates for P-glycoprotein and multidrug resistance-associated protein 1. P-glycoprotein and multidrug resistance-associated protein 1 protect colonic epithelial cells against xenobiotics. The aim of this study was to analyse the interference of anthranoids with these natural defence mechanisms and the direct cytotoxicity of anthranoids in cancer cell lines expressing these mechanisms in varying combinations. A cytotoxicity profile of rhein, aloe emodin and danthron was established in related cell lines exhibiting different levels of topoisomerases, multidrug resistance-associated protein 1 and P-glycoprotein. Interaction of rhein with multidrug resistance-associated protein 1 was studied by carboxy fluorescein efflux and direct cytotoxicity by apoptosis induction. Rhein was less cytotoxic in the multidrug resistance-associated protein 1 overexpressing GLC4/ADR cell line compared to GLC4. Multidrug resistance-associated protein 1 inhibition with MK571 increased rhein cytotoxicity. Carboxy fluorescein efflux was blocked by rhein. No P-glycoprotein dependent rhein efflux was observed, nor was topoisomerase II responsible for reduced toxicity. Rhein induced apoptosis but did not intercalate DNA. Aloe emodin and danthron were no substrates for MDR mechanisms. Rhein is a substrate for multidrug resistance-associated protein 1 and induces apoptosis. It could therefore render the colonic epithelium sensitive to cytotoxic agents, apart from being toxic in itself

The digital music lab: A big data infrastructure for digital musicology

In musicology and music research generally, the increasing availability of digital music, storage capacities, and computing power enable and require new and intelligent systems. In the transition from traditional to digital musicology, many techniques and tools have been developed for the analysis of individual pieces of music, but large-scale music data that are increasingly becoming available require research methods and systems that work on the collection-level and at scale. Although many relevant algorithms have been developed during the past 15 years of research in Music Information Retrieval, an integrated system that supports large-scale digital musicology research has so far been lacking. In the Digital Music Lab (DML) project, a collaboration among music librarians, musicologists, computer scientists, and human-computer interface specialists, the DML software system has been developed that fills this gap by providing intelligent large-scale music analysis with a user-friendly interactive interface supporting musicologists in their exploration and enquiry. The DML system empowers musicologists by addressing several challenges: distributed processing of audio and other music data, management of the data analysis process and results, remote analysis of data under copyright, logical inference on the extracted information and metadata, and visual web-based interfaces for exploring and querying the music collections. The DML system is scalable and based on SemanticWeb technology and integrates into Linked Data with the vision of a distributed system that enables music research across archives, libraries, and other providers of music data. A first DML system prototype has been set up in collaboration with the British Library and I Like Music Ltd. This system has been used to analyse a diverse corpus of currently 250,000 music tracks. In this article, we describe the DML system requirements, design, architecture, components, and available data sources, explaining their interaction. We report use cases and applications with initial evaluations of the proposed system

ON STABLE SELF–SIMILAR BLOW UP FOR EQUIVARIANT WAVE MAPS: THE LINEARIZED PROBLEM

We consider co–rotational wave maps from (3 + 1) Minkowski space into the three– sphere. This is an energy supercritical model which is known to exhibit finite time blow up via self–similar solutions. The ground state self–similar solution f0 is known in closed form and based on numerics, it is supposed to describe the generic blow up behavior of the system. In this paper we develop a rigorous linear perturbation theory around f0. This is an indispensable prerequisite for the study of nonlinear stability of the self–similar blow up which is conducted in the companion paper [11]. In particular, we prove that f0 is linearly stable if it is mode stable. Furthermore, concerning the mode stability problem, we prove new results that exclude the existence of unstable eigenvalues with large imaginary parts and also, with real parts larger than 1 2. The remaining compact region is well–studied numerically and all available results strongly suggest the nonexistence of unstable modes