A Fragmented Parallel Stream: The Bass Lines of Eddie Gomez in the Bill Evans Trio

Eddie Gomez was the bassist in the Bill Evans Trio for eleven years. His contribution to the group’s sound was considerable, but while there has been some recognition of his virtuoso solos in the trio there has been little academic interest in his bass lines. This essay examines bass lines from the album Since We Met, recorded in 1974 by Evans, Gomez and drummer Marty Morell. Analysis of the bass accompaniments to the piano solos on “Since We Met” and “Time Remembered” reveals that they form a fragmented two-feel. A traditional two-feel employs two notes to emphasise the first and third beats in bar of 4/4 time. In Gomez’s bass lines these two notes are frequently replaced with short rhythmic motifs. These motifs occur in a variety of forms and at different metric displacements that alternately propel and retard the forward motion of the music. Additionally, Gomez uses a wide range of register and varied articulations to create a richly diverse bass line. The resulting effect has often been interpreted as interactive or conversational with the soloist. However there is very little interaction between the bass line and Evans’ solo. The bass line is a parallel stream to the solo that energises and colours the music

Novel genetic loci associated with hippocampal volume

The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness

Genetic factors and the brain in ADHD

Contains fulltext : 135625.pdf (publisher's version ) (Open Access)Radboud Universiteit Nijmegen, 12 februari 2015Promotores : Buitelaar, J.K., Franke, B. Co-promotores : Arias Vasquez, A., Greven, C.U

Shared genetic influences on resting-state functional networks of the brain

The amplitude of activation in brain resting state networks (RSNs), measured with resting-state functional magnetic resonance imaging, is heritable and genetically correlated across RSNs, indicating pleiotropy. Recent univariate genome-wide association studies (GWASs) explored the genetic underpinnings of individual variation in RSN activity. Yet univariate genomic analyses do not describe the pleiotropic nature of RSNs. In this study, we used a novel multivariate method called genomic structural equation modeling to model latent factors that capture the shared genomic influence on RSNs and to identify single nucleotide polymorphisms (SNPs) and genes driving this pleiotropy. Using summary statistics from GWAS of 21 RSNs reported in UK Biobank (N = 31,688), the genomic latent factor analysis was first conducted in a discovery sample (N = 21,081), and then tested in an independent sample from the same cohort (N = 10,607). In the discovery sample, we show that the genetic organization of RSNs can be best explained by two distinct but correlated genetic factors that divide multimodal association networks and sensory networks. Eleven of the 17 factor loadings were replicated in the independent sample. With the multivariate GWAS, we found and replicated nine independent SNPs associated with the joint architecture of RSNs. Further, by combining the discovery and replication samples, we discovered additional SNP and gene associations with the two factors of RSN amplitude. We conclude that modeling the genetic effects on brain function in a multivariate way is a powerful approach to learn more about the biological mechanisms involved in brain function

Discovering the shared biology of cognitive traits determined by genetic overlap

Contains fulltext : 217332.pdf (publisher's version ) (Open Access

Predicting attention-deficit/hyperactivity disorder severity from psychosocial stress and stress-response genes: a random forest regression approach

Contains fulltext : 174504.pdf (publisher's version ) (Open Access)Identifying genetic variants contributing to attention-deficit/hyperactivity disorder (ADHD) is complicated by the involvement of numerous common genetic variants with small effects, interacting with each other as well as with environmental factors, such as stress exposure. Random forest regression is well suited to explore this complexity, as it allows for the analysis of many predictors simultaneously, taking into account any higher-order interactions among them. Using random forest regression, we predicted ADHD severity, measured by Conners' Parent Rating Scales, from 686 adolescents and young adults (of which 281 were diagnosed with ADHD). The analysis included 17 374 single-nucleotide polymorphisms (SNPs) across 29 genes previously linked to hypothalamic-pituitary-adrenal (HPA) axis activity, together with information on exposure to 24 individual long-term difficulties or stressful life events. The model explained 12.5% of variance in ADHD severity. The most important SNP, which also showed the strongest interaction with stress exposure, was located in a region regulating the expression of telomerase reverse transcriptase (TERT). Other high-ranking SNPs were found in or near NPSR1, ESR1, GABRA6, PER3, NR3C2 and DRD4. Chronic stressors were more influential than single, severe, life events. Top hits were partly shared with conduct problems. We conclude that random forest regression may be used to investigate how multiple genetic and environmental factors jointly contribute to ADHD. It is able to implicate novel SNPs of interest, interacting with stress exposure, and may explain inconsistent findings in ADHD genetics. This exploratory approach may be best combined with more hypothesis-driven research; top predictors and their interactions with one another should be replicated in independent samples

CR1 genotype is associated with entorhinal cortex volume in young healthy adults

Item does not contain fulltextGene-brain structure associations of 3 recently discovered risk genes for Alzheimer's disease, CLU (rs11136000C>T), CR1 (rs6656401G>A), and PICALM (rs3851179G>A), were investigated in 2 independent cohorts of young healthy adults (n = 430 and n = 492, respectively). We assessed structural differences in 2 core structures of Alzheimer pathology, entorhinal cortex and hippocampus, by voxel-based morphometry using high-resolution magnetic resonance imaging (MRI) data. For CLU and PICALM no significant genotype-related differences in local gray matter volume were found. CR1 risk allele (A) carriers showed smaller local gray matter volume in the entorhinal cortex, as confirmed in both cohorts. This association, apparent in young healthy adults, might mediate susceptibility for Alzheimer's disease later in life

Association of the Alzheimer's gene SORL1 with hippocampal volume in young, healthy adults

Item does not contain fulltextOBJECTIVE: Alzheimer's disease is among the most common neurodegenerative disorders. The SORL1 (sortilin receptor 1) gene is associated with the disease, but different variants seem to contribute. The authors used a gene-wide approach to test whether SORL1 is associated with volume of the hippocampus, one of the first structures to be affected by Alzheimer's disease in young, healthy individuals, in an attempt to map potential pathways from gene to disease. METHOD: Individuals were genotyped using an array-based method, and a total of 117 single nucleotide polymorphisms (SNPs) in and surrounding SORL1 were included in the analysis. Through the use of a brain segmentation protocol, SNP-by-SNP and gene-wide associations with bilateral hippocampal volume were assessed in two large, independent samples consisting of 446 (discovery cohort) and 490 (replication cohort) healthy young individuals. RESULTS: Significant association of the SORL1 gene with hippocampal volume was observed in both the discovery and replication samples as well as in the combined sample. The gene-wide association was independent of the apolipoprotein E genotype and resistant to removal of four significantly associated single SNPs. CONCLUSIONS: This study provides the first evidence that the SORL1 gene is associated with differences in hippocampal volume in young, healthy adults. It is demonstrated that gene-wide analysis techniques may overcome power problems caused by allelic heterogeneity in association studies. The results support the hypothesis that the SORL1 gene contributes to an increased risk for Alzheimer's disease through effects on hippocampal volume

ADHD symptoms in the adult general population are associated with factors linked to ADHD in adult patients

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder in children and adults. It is characterized by inappropriate levels of inattention (IA) and/or hyperactivity and impulsivity (HI). The ADHD diagnosis is hypothesized to represent the extreme of a continuous distribution of ADHD symptoms in the general population. In this study, we investigated whether factors linked to adult ADHD as a disorder are associated with adult ADHD symptoms in the general population. Our population-based sample included 4987 adults (mean age 56.1 years; 53.8% female) recruited by the Nijmegen Biomedical Study (NBS). Participants completed the Dutch ADHD DSM-IV Rating Scale for current and childhood ADHD symptoms, the Symptom Check List-90-R (SCL-90-R) anxiety subscale, and the Eysenk Personality Questionnaire (EPQR-S). Partial Spearman correlation and Hurdle negative binomial regression analysis were used to assess how age, sex, childhood ADHD symptoms, anxiety symptoms, and personality traits (neuroticism, extraversion, and psychoticism) are associated with current IA and HI symptoms. Increasing age was associated with a lower proportion of participants reporting HI symptoms and with reduced levels of HI; IA levels remained fairly stable over the age-range, but the probability of reporting IA symptoms increased throughout middle/late adulthood. Females were more likely to report IA symptoms than males. Childhood ADHD symptoms, neuroticism, and psychoticism were positively associated with current IA and HI symptoms, while extraversion had an opposite association with these symptom domains. Anxiety symptoms affected HI symptoms in females. Our results indicate that factors associated with categorical ADHD are also correlated with ADHD symptoms in the adult population

Genome-wide association study of pediatric obsessive-compulsive traits: shared genetic risk between traits and disorder

Contains fulltext : 231401.pdf (publisher's version ) (Open Access