Classification of Triadic Chord Inversions Using Kohonen Self-organizing Maps

In this paper we discuss the application of the Kohonen Selforganizing Maps to the classification of triadic chords in inversions and root positions. Our motivation started in the validation of Schönberg´s hypotheses of the harmonic features of each chord inversion. We employed the Kohonen network, which has been generally known as an optimum pattern classification tool in several areas, including music, to verify that hypothesis. The outcomes of our experiment refuse the Schönberg´s assumption in two aspects: structural and perceptual/functional

Paisagem Sonora: uma proposta de análise

This paper discuss the use of environmental sounds in musical composition, specially in the so-called Soundscape music. The use of such sounds in compositions created with technological support after the 60’s have started a controversial discussion on the musical syntax that such sounds can generate. The environmental sounds also raised important debates related to theories of auditory perception. Related to this point we present the processes of listening based on the ecological approach to auditory perception, which comes from J. J. Gibson’s theory of direct perception. This theory is taken as base to a new approach to environmental sonic materials and its insertion in the compositional processes. Our goal is to raise the issues that had lead to all those problems, and to briefly expose the theory of direct perception of J.J. Gibson as well. We conclude showing a possibility to use the notions of the ecological approach to perception as alternative analytic tools for soundscape music

Computational assessment of insulin secretion and insulin sensitivity from 2-h oral glucose tolerance tests for clinical use for type 2 diabetes

In type 2 diabetes mellitus, glucose homeostasis is tightly maintained through insulin secretion and insulin sensitivity. Therefore, finding an accurate method to assess insulin secretion and sensitivity using clinically available data would enhance the quality of diabetic medical care. In an effort to find such a method, we developed a computational approach to derive indices of these factors using a 2-h oral glucose tolerance test (OGTT). To evaluate our method, clinical data from subjects who received an OGTT and a glucose clamp test were examined. Our insulin secretion index was significantly correlated with an analogous index obtained from a hyperglycemic clamp test (r = 0.90, n = 46, p < 0.001). Our insulin sensitivity index sensitivity was also significantly correlated with an analogous index obtained from a hyperinsulinemic-euglycemic clamp test (r = 0.56, n = 79, p < 0.001). These results suggest that our method can potentially provide an accurate and convenient tool toward improving the management of diabetes in clinical practice by assessing insulin secretion and insulin sensitivity

Differential properties of transcriptional complexes formed by the CoREST family

Mammalian genomes harbor three CoREST genes. rcor1 encodes CoREST (CoREST1) and the paralogues rcor2 and rcor3 encode CoREST2 and CoREST3, respectively. Here, we describe specific properties of transcriptional complexes formed by CoREST proteins with the histone demethylase LSD1/KDM1A and histone deacetylases HDAC1/2 and the finding that all three CoRESTs express in the adult rat brain. CoRESTs interact equally strong with LSD1/KDM1A. Structural analysis shows that the overall conformation of CoREST3 is similar to that of CoREST1 complexed with LSD1/KDM1A. Nonetheless, transcriptional repressive capacity of CoREST3 is lower than that of CoREST1, which correlates with the observation that CoREST3 leads to a reduced LSD1/KDM1A catalytic efficiency. Also, CoREST2 shows a lower transcriptional repression than CoREST1, which is resistant to HDAC inhibitors. CoREST2 displays lower interaction with HDAC1/2 which is barely present in LSD1/KDM1A-CoREST2 complexes. A non-conserved Leucine in the first SANT domain of CoREST2 severely weakens its association to HDAC1/2. Furthermore, CoREST2 mutants with either increased or lacking HDAC1/2 interaction feature equivalent transcriptional repression capacities, indicating that CoREST2 represses in a HDAC-independent manner. In conclusion, differences among CoREST proteins are instrumental to the modulation of protein-protein interactions and catalytic activities of LSD1/KDM1A-CoREST-HDAC complexes, fine tuning gene expression regulation

Common Genetic Variation in GLP1R and Insulin Secretion in Response to Exogenous GLP-1 in Nondiabetic Subjects: A pilot study

OBJECTIVE: Glucagon-like peptide (GLP)-1 receptor is encoded by GLP1R. The effect of genetic variation at this locus on the response to GLP-1 is unknown. This study assessed the effect of GLP1R polymorphisms on insulin secretion in response to hyperglycemia and to infused GLP-1 in nondiabetic subjects. RESEARCH DESIGN AND METHODS: Eighty-eight healthy individuals (aged 26.3 +/- 0.6 years, fasting glucose 4.83 +/- 0.04 mmol/l) were studied using a hyperglycemic clamp. GLP-1 was infused for the last 2 h of the study (0.75 pmol/kg/min over 121-180 min, 1.5 pmol/kg/min over 181-240 min). beta-Cell responsivity (Phi(Total)) was measured using a C-peptide minimal model. The effect of 21 tag single nucleotide polymorphisms (SNPs) in GLP1R on Phi(Total) was examined. RESULTS: Two SNPs (rs6923761 and rs3765467) were nominally associated with altered beta-cell responsivity in response to GLP-1 infusion. CONCLUSIONS: Variation in GLP1R may alter insulin secretion in response to exogenous GLP-1. Future studies will determine whether such variation accounts for interindividual differences in response to GLP-1-based therapy

Dipeptidyl Peptidase-4 Inhibition by Vildagliptin and the Effect on Insulin Secretion and Action in Response to Meal Ingestion in Type 2 Diabetes

OBJECTIVE—The purpose of this study was to determine the mechanism by which dipeptidyl peptidase-4 inhibitors lower postprandial glucose concentrations