Discriminating music performers by timbre: On the relation between instrumental gesture, tone quality and perception in classical cello performance

Classical music performers use instruments to transform the symbolic notationof the score into sound which is ultimately perceived by a listener. For acoustic instruments, the timbre of the resulting sound is assumed to be strongly linked to the physical and acoustical properties of the instrument itself. However, rather little is known about how much influence the player has over the timbre of the sound — is it possible to discriminate music performers by timbre? This thesis explores player-dependent aspects of timbre, serving as an individual means of musical expression. With a research scope narrowed to analysis of solo cello recordings, the differences in tone quality of six performers who played the same musical excerpts on the same cello are investigated from three different perspectives: perceptual, acoustical and gestural. In order to understand how the physical actions that a performer exerts on an instrument affect spectro-temporal features of the sound produced, which then can be perceived as the player’s unique tone quality, a series of experiments are conducted, starting with the creation of dedicated multi-modal cello recordings extended by performance gesture information (bowing control parameters). In the first study, selected tone samples of six cellists are perceptually evaluated across various musical contexts via timbre dissimilarity and verbal attribute ratings. The spectro-temporal analysis follows in the second experiment, with the aim to identify acoustic features which best describe varying timbral characteristics of the players. Finally, in the third study, individual combinationsof bowing controls are examined in search for bowing patterns which might characterise each cellist regardless of the music being performed. The results show that the different players can be discriminated perceptually, by timbre, and that this perceptual discrimination can be projected back through the acoustical and gestural domains. By extending current understanding of human-instrument dependencies for qualitative tone production, this research may have further applications in computer-aided musical training and performer-informed instrumental sound synthesis.This work was supported by a UK EPSRC DTA studentship EP/P505054/1 and the EPSRC funded OMRAS2 project EP/E017614/1

Neutron irradiation of coated conductors

Various commercial coated conductors were irradiated with fast neutrons in order to introduce randomly distributed, uncorrelated defects which increase the critical current density, Jc, in a wide temperature and field range. The Jc-anisotropy is significantly reduced and the angular dependence of Jc does not obey the anisotropic scaling approach. These defects enhance the irreversibility line in not fully optimized tapes, but they do not in state-of-the-art conductors. Neutron irradiation provides a clear distinction between the low field region, where Jc is limited by the grain boundaries, and the high field region, where depinning leads to dissipation

A comprehensive view of the epigenetic landscape part I : DNA methylation, passive and active DNA demethylation pathways and histone variants

In multicellular organisms, all the cells are genetically identical but turn genes on or off at the right time to promote differentiation into specific cell types. The regulation of higher-order chromatin structure is essential for genome-wide reprogramming and for tissue-specific patterns of gene expression. The complexity of the genome is regulated by epigenetic mechanisms, which act at the level of DNA, histones, and nucleosomes. Epigenetic machinery is involved in many biological processes, including genomic imprinting, X-chromosome inactivation, heterochromatin formation, and transcriptional regulation, as well as DNA damage repair. In this review, we summarize the recent understanding of DNA methylation, cytosine derivatives, active and passive demethylation pathways as well as histone variants. DNA methylation is one of the well-characterized epigenetic signaling tools. Cytosine methylation of promoter regions usually represses transcription but methylation in the gene body may have a positive correlation with gene expression. The attachment of a methyl group to cytosine residue in the DNA sequence is catalyzed by enzymes of the DNA methyltransferase family. Recent studies have shown that the Ten-Eleven translocation family enzymes are involved in stepwise oxidation of 5-methylcytosine, creating new cytosine derivatives including 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxylcytosine. Additionally, histone variants into nucleosomes create another strategy to regulate the structure and function of chromatin. The replacement of canonical histones with specialized histone variants regulates accessibility of DNA, and thus may affect multiple biological processes, such as replication, transcription, DNA repair, and play a role in various disorders such as cancer

The Rostock Energetic Feed Evaluation on the Base of Net Energy

Feed evaluation was an emphasis of research from the foundation of the Oskar-Kellner-Institute of Animal Nutrition in 1953 at Rostock by Prof. Kurt Nehring. The aim of the research work was the elaboration of a feed evaluation system containing reference numbers of feed values and requirements of farm animals. The approach and the present system are outlined in this paper

A Comprehensive View of the Epigenetic Landscape Part I: DNA Methylation, Passive and Active DNA Demethylation Pathways and Histone Variants

In multicellular organisms, all the cells are genetically identical but turn genes on or off at the right time to promote differentiation into specific cell types. The regulation of higher-order chromatin structure is essential for genome-wide reprogramming and for tissue-specific patterns of gene expression. The complexity of the genome is regulated by epigenetic mechanisms, which act at the level of DNA, histones, and nucleosomes. Epigenetic machinery is involved in many biological processes, including genomic imprinting, X-chromosome inactivation, heterochromatin formation, and transcriptional regulation, as well as DNA damage repair. In this review, we summarize the recent understanding of DNA methylation, cytosine derivatives, active and passive demethylation pathways as well as histone variants. DNA methylation is one of the well-characterized epigenetic signaling tools. Cytosine methylation of promoter regions usually represses transcription but methylation in the gene body may have a positive correlation with gene expression. The attachment of a methyl group to cytosine residue in the DNA sequence is catalyzed by enzymes of the DNA methyltransferase family. Recent studies have shown that the Ten-Eleven translocation family enzymes are involved in stepwise oxidation of 5-methylcytosine, creating new cytosine derivatives including 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxylcytosine. Additionally, histone variants into nucleosomes create another strategy to regulate the structure and function of chromatin. The replacement of canonical histones with specialized histone variants regulates accessibility of DNA, and thus may affect multiple biological processes, such as replication, transcription, DNA repair, and play a role in various disorders such as cancer

Collaborative study to evaluate a candidate World Health Organization international standard for chikungunya virus for nucleic acid amplification technique (NAT)-based assays

Collaborative Study Group - Portugal:Maria João Alves, Líbia Zé-Zé (National Institute of Health Dr. Ricardo Jorge, Center for Vectors and Infectious Diseases Research)This report describes the World Health Organization (WHO) project to develop an international standard (IS) for Chikungunya virus (CHIKV) RNA for use with nucleic acid amplification technique (NAT)-based assays. An international collaborative study was conducted to determine the potency of the candidate standard using a range of NAT-based assays for CHIKV, and to evaluate the suitability of the candidate for the calibration of secondary reference materials and the standardization of CHIKV viral load measurements. The candidate standard consisted of a heat inactivated CHIKV strain of the East/South/Central African genotype (ESCA), also known as the Indian Ocean Lineage, isolated from a patient returning from India to the United States in 20061 , diluted in human negative plasma. The lyophilized candidate preparation (Sample 1), the corresponding liquid-frozen bulk material (Sample 2) and three different clinical samples (Sample 3, Sample 4 and Sample 5) were included in the collaborative study. Twenty-five laboratories representing 14 countries participated in the study to evaluate the material using their routine CHIKV NAT assays. Twenty-four laboratories returned 31 data sets from 17 commercial assays and 14 in-house methods. Of these 31 methods, 11 were quantitative and 20 were qualitative. The results of the study indicate the suitability of the candidate material of the CHIKV strain of ESCA genotype (Sample 1) as the proposed 1st WHO IS for CHIKV. It is therefore proposed that the candidate material (PEI code 11785/16) is established as the 1st WHO IS for CHIKV RNA for NAT-based assays with an assigned potency of 2,500,000 International Units (IU)/mL when reconstituted in 0.5 mL of nuclease-free water. On-going studies for real-time and accelerated stability of the proposed IS indicate that the preparation is stable and suitable for long-term use under the proposed storage conditions.info:eu-repo/semantics/publishedVersio

Histopathological changes in female rabbits administered with aqueous extract of Calotropis procera

Calotropis procera is an evergreen perennial shrub, which is found mainly in the arid regions and produces copious latex when cut. It has been reported to possess medicinal properties but equally pose deleterious effect in animals. In a bid to exploit its pharmacological properties, it was necessary to ascertain its level of safety. A toxicological evaluation of the aqueous extract of fresh leaves of the plant was therefore conducted in the more sensitive female rabbits of the same weight range. Low levels of phytochemicals (alkaloids, saponins, tannins, cardiac glycosides and flavonoids) were found, while elemental analyses showed traces of iron, lead, sodium, and potassium in concentrations of 0.23, 0.03, 0.82 and 9.5 mg/g, respectively. Acute toxicity study was conducted with oral administration of 200, 400, 800 and 1600 mg/kg of the extract once to groups I, II, III and IV, respectively with a 24 h observation period. Clinical signs such as mouth chewing, photophobia, bradycardia, coughing, vomiting and convulsion amongst others were noticed. Four rabbits died within 24 h and LD50 was estimated (940 mg/kg). 80, 40 and 20 mg/kg of the extract were administered daily to groups I, II, and III, respectively, during sub-acute toxicity study for 14 days. Grossly, catarrhal enteritis and mesenteric congestion of the small intestines, congestion of the lungs, hepatization and paleness of the liver, congestion and pallor of the kidney cortex, and congestion of the meninges were noticed. Histopathological examination of the tissues revealed mild pulmonary oedema and peribronchial lymphocytic infiltration of the lungs, hepatization of the liver, disruption of cardiac architecture, generalised cell necrosis and erosion of the villi of the small intestine. All the rabbits that survived gained weight, which is indicative of some nutrient value in the extract. It was concluded that the extract had dose-dependent deleterious effects on the tissues as higher dose groups were more affected. Hence, it is evident that sub-chronic toxicity studies would reveal greater lesions to better ascertain extent of damage.Key words: Calotropis procera, phytochemical, histopathology, toxicity, lesions, tissues, organs