Characterization of a novel miniature cell culture device

Recent advancements in the field of microfluidics have generated much interest in the advent of a miniaturized cell culture device. In this study, we developed a novel miniature culture system for the continuous long-term cultivation of both anchorage dependent and suspension cells, either prokaryotic or eukaryotic in type, for both 1 g and microgravity applications. The miniature culture system may advance the development of microanalytical remote monitoring tools such as biological sentinels, biosensors, and lab-on-a-chip. Integrating the autonomous miniature culture system with a microanalytical device makes a powerful biological tool. Cells can be cultured long-term, harvested, and released directly into an analytical tool without the need for human interaction through fluid dynamic manipulations. This work characterizes the miniature bioreactor system through numerical and experimental proof of concept studies.     

The menagerie of geospace plasma waves

Sounding rockets and satellites have discovered a large variety of plasma waves within the Earth's magnetosphere—geospace. These waves are found over a frequency range of millihertz to megahertz. The frequency ranges are generally associated with characteristic frequencies such as the plasma frequency and gyrofrequency. Most waves are generated by hot or streaming magnetospheric plasma; some waves are due to lightning discharges, to intentional man-made transmitters or to incidental radiation from power transmission systems. Propagation of waves from the observation region back to a probable source region can be modelled using ray tracing techniques in a model magnetosphere where the electron number density, ion composition and magnetic field vector is specified. Information in addition to the common amplitude-frequency-time spectrograms can be obtained from the received waves using multiple antennas and receivers. Cross-correlation of the wave electric and magnetic components can provide information on the wave polarization and direction of propagation and on the wave distribution function.