Imaging genetics : Methodological approaches to overcoming high dimensional barriers

Imaging genetics is still a quite novel area of research which attempts to discover how genetic factors affect brain structures and functions. In this thesis, using a various methodological approaches I showed how it can contribute to our understanding of the complex genetic architecture of the human brain

Scanning Electron Microscopy Observation of the Voltage Contrast Image of the Ferroelectric Domain Structure in the LiNbO3 Crystal

This paper reports a scanning electron microscopy study of the formation of the voltage contrast image of the ferroelectric domain structure in the LiNbO3 crystal. We investigated the formation of the pyroelectric voltage contrast image of the regular domain structure. For our experiment, we used ZY cut of a LiNbO3 crystal which had a regular domain structure with a domain width of -55 μm. The regular domain structure in the LiNbO3 crystal was formed by the method of thermo-electrical treatment after growth. The pyroelectric voltage contrast image of the regular domain structure in the scanning electron microscope was formed by applying the pyroelectric effect along polar axis Z. The difference in the voltage contrast in the neighboring domains connect with opposite directions of polar axis Z in the neighboring domains. It is shown that the voltage contrast of the ferroelectric domain structures is defined by the physical properties and orientation of the ferroelectric crystals

Correlated two-photon emission by transitions of Dirac-Volkov states in intense laser fields: QED predictions

In an intense laser field, an electron may decay by emitting a pair of photons. The two photons emitted during the process, which can be interpreted as a laser-dressed double Compton scattering, remain entangled in a quantifiable way: namely, the so-called concurrence of the photon polarizations gives a gauge-invariant measure of the correlation of the hard gamma rays. We calculate the differential rate and concurrence for a backscattering setup of the electron and photon beam, employing Volkov states and propagators for the electron lines, thus accounting nonperturbatively for the electron-laser interaction. The nonperturbative results are shown to differ significantly compared to those obtained from the usual double Compton scattering.Comment: 32 pages, 12 figure