Abelian subgroups of \Out(F_n)

We classify abelian subgroups of Out(F_n) up to finite index in an algorithmic and computationally friendly way. A process called disintegration is used to canonically decompose a single rotationless element \phi into a composition of finitely many elements and then use these elements to generate an abelian subgroup A(\phi) that contains \phi. The main theorem is that up to finite index every abelian subgroup is realized by this construction. As an application we classify, up to finite index, abelian subgroups of Out(F_n) and of IA with maximal rank.Comment: 56 page

Toward a More Scientifically Literate Public

As a society we do a terrible job of educating our children to become scientifically literate. Sure, we have STEM (Science, Technology, Engineering and Mathematics) programs throughout the country, and with some justification we can brag about the successes of students that are in or who have graduated from such learning experiences

Don\u27t Just Blindly Follow All \u27Green\u27 Trends -- Do Your Research First

Nowadays it is politically correct to be “green” – to say and do things that seem to minimize one’s impact on the environment and to preach to others to do the same

Surface Detection fro Airports DIV

A surface detection system for airport facilities is described wherein a plurality of infrared (IR) scanners as well as presence/absence detectors are located with respect to taxiways and runways of an airport complex. These devices are arranged to perform in conjunction with local processors to generate data from aircraft and ground based vehicles available from a bar coding identification of both forms of vehicles. These data are utilized to compute alert conditions as well as to develop a real time map of the airport which may be provided at a tower installation for air traffic control utilization as well as at an aircraft flight deck during the course of ground maneuvering. Through the Utilization of aircraft tail numbers as an index, a master host memory may be developed which includes flight numbers, aircraft characteristics and the like which may be employed for evolving alert conditions and the like

How Did We Wind Up in Such an Unlikely Universe?

Not long ago the Public Broadcasting Service program NOVA presented an episode called “The Great Math Mystery.” It dealt with the many ways mathematical relationships and special numbers crop up when investigating the physical and natural world

Serious Men

This thesis is a Fiction story collection written in fulfillment of the Master of Fine Arts in Creative Writing at the University of New Orleans

Physical studies of adenylosuccinate synthetase

To determine the chemical mechanism of the reaction catalyzed by adenylosuccinate synthetase, positional isotope exchange studies were performed. Positional isotope exchange from the (beta)-(gamma) bridge to the (beta) nonbridge position of (gamma)-(\u2718)O GTP was followed using (\u2731)P NMR. The positional isotope exchange was found to occur in the presence of either IMP or IMP and succinate. The exchange did not occur in the presence of asparate. These results support a reaction mechanism which involves formation of a 6-phosphoryl-IMP intermediate with subsequent attack by aspartate to form adenylosuccinate as originally proposed by Lieberman in 1956 Lieberman, I. J. Biol. Chem., 1956, 223, 327-339 ;In order to resolve the NMR resonances for positional isotope exchange, it was necessary to find a chelator which would limit exchange broadening. trans-1,2-Diaminocyclohexane-N,N,N\u27,N\u27-tetraacetic acid was found to be a suitable chelator at neutral and acidic pH;Studies of adenylosuccinate synthetase from Escherichia coli have been limited by the low concentrations of enzyme present in the cell and the difficulty in purifying the enzyme to homogeneity. Overproduction of the enzyme by cloning the purA gene into a runaway replication plasmid allowed the cells to produce a much higher concentration of enzyme. A new purification scheme is reported that takes advantage of the overproduced enzyme. Yields of 75 mg of homogeneous enzyme have been obtained from 76 g of E. coli cell paste

Low voltage display or indicator systems employing combinations of up converters and semiconductor light sources.

Methods and systems for a combination of up converters and semiconductor light sources in low voltage display or indicator system that can be battery powered. The display or indicator system includes one or more spatial light modulators and one or more up converters in combination with one or more semiconductor light sources. The spatial light modulator can be a liquid crystal display or a micro electro mechanical system or other spatial light modulator and can use direct modulation of the semiconductor light sources to modulate the visible emission from the up converters. The spatial light modulator can be placed between the up converting light source and the viewer or behind the up converting light source depending on the type of spatial light modulator, or modulation may be applied directly to one or more semiconductor light sources or arrays of semiconductor light sources that excite the up converters

Combination of up-converting materials with semiconductor light sources

Methods, apparatus and systems for an up-converter resonant cavity light emitting diode device includes a semiconductor light source, an up-converter to form the light emitter with up-converting materials and an electrical source coupled with the semiconductor light source for providing electrical energy to the semiconductor light source to provide a desired wavelength emitted light. The semiconductor light source is a resonant cavity light emitting diode or laser that emits an approximately 975 nm wavelength to provide electrical and optical confinement to the semiconductor light source to form an up-converting resonant cavity light emitting diode (UCIRCLED). Rows and columns of electrodes provide active matrix addressing of plural sets of UCIRCLEDs for display devices. The up-converter resonant cavity light emitting diode device has applications in head mounted projection display optical system using spectrally selective beam splitters to eliminate spectral overlap between colors a

Composite cavity for enhanced efficiency of up conversion.

Methods, apparatus and systems for an up-converter resonant cavity light emitting diode device includes a semiconductor light source, an up-converter to form the light emitter with up-converting materials and an electrical source coupled with the semiconductor light source for providing electrical energy to the semiconductor light source to provide a desired wavelength emitted light. The semiconductor light source is a resonant cavity light emitting diode or laser that emits an approximately 975 nm wavelength to provide electrical and optical confinement to the semiconductor light source to fonn a resonant cavity up-converting light emitting diode (UCIRCLED). Rows and columns of electrodes provide active matrix addressing of plural sets of UC/RCLEDs for display devices. The up-converter resonant cavity light emitting diode device has applications in head mounted projection display optical system using spectrally selective beam splitters to eliminate spectral overlap between colors a