Genetic Overlap and Causal Mediation Relationship Between Psychiatric and Non-Psychiatric Phenotypes

Genome-wide genotyping studies are providing evidence that psychiatric disorders are truly polygenic, that is they have a genetic architecture of many genetic variants. Cross-trait polygenic analysis has been applied to identifying genetic correlations between psychiatric and non-psychiatric phenotypes. However, causal models between shared genetic factors and the genetically-correlated phenotypes are mostly unclear. We used cross-trait polygenic risk score (PRS) association analysis to examine the genetic overlap between two phenotypes. We then performed causal mediation analysis to identify the causal relationship between common genetic variants and two genetically correlated traits. We examined if the effect of polygenic risk on one trait (i.e., the outcome) was mediated by the other trait (i.e., the mediator). In Chapter 1, we examined the relationship between PRS for psychotic illness or cognitive ability, event-related potential (ERP), and severity of psychotic symptoms. A phenotype of global impairment on multiple ERP measures is associated with positive symptoms of psychosis as well as polygenic influences on educational attainment and, to a lesser extent, schizophrenia. We also observed a positive association between education PRS and positive symptoms that was almost entirely mediated by effects on the globally impaired ERP phenotype. In Chapter 2, we examined the relationship between PRS for Alzheimer’s dementia, vascular pathologies, and late-life cognitive function. Our findings support the hypothesis of a genetic overlap, mostly due to APOE, between vascular pathologies and AD dementia. The polygenic genetic effect on late-life cognition is partially but significantly mediated by cerebral microbleeds, white matter lesion load, and coronary artery calcification. In Chapter 3, we examined the relationship between PRS for coronary heart disease, psychological attitudes, and liability to coronary heart disease. Our findings suggest a genetic overlap between optimism and CHD in older women of European ancestry. The polygenic genetic effect on CHD is modestly though significantly mediated by optimism

Dynamical Instability of Holographic QCD at Finite Density

In this paper we study the dynamical instability of Sakai-Sugimoto's holographic QCD model at finite baryon density. In this model, the baryon density, represented by the smeared instanton on the worldvolume of the probe D8-\overline{D8} mesonic brane, sources the worldvolume electric field, and through the Chern-Simons term it will induces the instability to form a chiral helical wave. This is similar to Deryagin-Grigoriev-Rubakov instability to form the chiral density wave for large N_c QCD at finite density. Our results show that this kind of instability occurs for sufficiently high baryon number densities. The phase diagram of holographic QCD will thus be changed from the one which is based only on thermodynamics. This holographic approach provides an effective way to study the phases of QCD at finite density, where the conventional perturbative QCD and lattice simulation fail.Comment: 18 pages, 6 figures;v2. add thermodynamics discussion; v4. Treatment of the instanton energy changed and QGP analysis added. Some figures replaced and added, including the phase diagra

Gender Determination using Fingerprint Features

Several previous studies have investigated the gender difference of the fingerprint features. However, regarding to the statistical significance of such differences, inconsistent results have been obtained. To resolve this problem and to develop a method for gender determination, this work proposes and tests three fingertip features for gender determination. Fingerprints were obtained from 115 normal healthy adults comprised of 57 male and 58 female volunteers. All persons were born in Taiwan and were of Han nationality. The age range was18-35 years. The features of this study are ridge count, ridge density, and finger size, all three of which can easily be determined by counting and calculation. Experimental results show that the tested ridge density features alone are not very effective for gender determination. However, the proposed ridge count and finger size features of left little fingers are useful, achieving a classification accuracy of 75% (P-valu

A Comparative Study for 2D and 3D Computer-aided Diagnosis Methods for Solitary Pulmonary Nodules

Many computer-aided diagnosis (CAD) methods, including 2D and 3D approaches, have been proposed for solitary pulmonary nodules (SPNs). However, the detection and diagnosis of SPNs remain challenging in many clinical circumstances. One goal of this work is to investigate the relative diagnostic accuracy of 2D and 3D methods. An additional goal is to develop a two-stage approach that combines the simplicity of 2D and the accuracy of 3D methods. The experimental results show statistically significant differences between the diagnostic accuracy of 2D and 3D methods. The results also show that with a very minor drop in diagnostic performance the two-stage approach can significantly reduce the number of nodules needed to be processed by the 3D method, streamlining the computational demand

The influence of expertise and experimental paradigms on the visual behavior of tennis athletes in returning a serve

To return a serve, one must pick up information from the server’s kinematics and anticipate the ball trajectory. Although the perceptual requirements are important, the literature diverges in terms of the differences between experts and novices as well as the importance of the experimental paradigm (in-situ vs. video-based) for the results. This study aimed to address both concerns. We compared experts’ (n=7, 20.6±1.1 years of age) and novices’ (n=7, 20.0±0.4 years of age) visual pattern when returning a serve (Experiment 1) and the influence of the experimental paradigm in experts (Experiment 2). Experts fixated more and longer the upper body and ball, while novices showed a more distributed pattern and with longer fixations outside of the server’s body. Also, the pattern was different when comparing in-situ and laboratory settings, differing mainly in fixation frequency. The influence of expertise was observed in qualitative (relative) and quantitative (absolute) measures of visual behavior with the setting having an important influence. Thus, studies should be as close to the actual situation if trying to understand experts’ behavior