The Republic of The Philippines: Epidemiology and Epigenetics

A brief, yet concise investigation was conducted on the Republic of the Philippines, with a keen interest in the epidemiology of the current urban areas of the nation (+150,000 inhabitants), as well as possible epigenetic change that may be induced from disease or environmental stressors upon these same groups of people. G6PD deficiency, a common disorder among persons in urban dwellings within the Republic of the Philippines (Hsia 1993) was found to have a strong correlation of incidence with members of other nations in localized proximity to the equator. Additionally, low birth weight in infants has been identified as a potential epigenetic cue in those of the emerging, current population (Kuzawa 2012).https://scholarscompass.vcu.edu/uresposters/1111/thumbnail.jp

Low-damping transmission of spin waves through YIG/Pt-based layered structures for spin-orbit-torque applications

We show that in YIG-Pt bi-layers, which are widely used in experiments on the spin transfer torque and spin Hall effects, the spin-wave amplitude significantly decreases in comparison to a single YIG film due to the excitation of microwave eddy currents in a Pt coat. By introducing a novel excitation geometry, where the Pt layer faces the ground plane of a microstrip line structure, we suppressed the excitation of the eddy currents in the Pt layer and, thus, achieved a large increase in the transmission of the Damon-Eshbach surface spin wave. At the same time, no visible influence of an external dc current applied to the Pt layer on the spin-wave amplitude in the YIG-Pt bi-layer was observed in our experiments with YIG films of micrometer thickness

Mechanisms of nonlinear spin-wave emission from a microwave driven nanocontact

We present a micromagnetic study of linear and nonlinear spin-wave modes excited in an extended permalloy thin film by a microwave driven nanocontact. We show that the linear mode having the frequency equal to the excitation frequency (f) is driven by the ac Oersted field component perpendicular to the static external field (applied in-plane of the sample). The nonlinear mode with the frequency f /2 is excited as an independent eigenmode within a parametric longitudinal pumping process (due ac Oersted field component parallel to the bias field). Spectral positions of those modes are determined both in the space and phase domain. The results are important for the transfer of information coded into spin-waves between nanocontacts, and for synchronization of spin transfer torque nano-oscillators.Comment: 5 pages, 4 figure

Tunable space-time crystal in room-temperature magnetodielectrics

We report the experimental realization of a space-time crystal with tunable periodicity in time and space in the magnon Bose-Einstein Condensate (BEC), formed in a room-temperature Yttrium Iron Garnet (YIG) film by radio-frequency space-homogeneous magnetic field. The magnon BEC is prepared to have a well defined frequency and non-zero wavevector. We demonstrate how the crystalline "density" as well as the time and space textures of the resulting crystal may be tuned by varying the experimental parameters: external static magnetic field, temperature, thickness of the YIG film and power of the radio-frequency field. The proposed space-time crystals provide a new dimension for exploring dynamical phases of matter and can serve as a model nonlinear Floquet system, that brings in touch the rich fields of classical nonlinear waves, magnonics and periodically driven systems