Nonlinear optimal guidance algorithms Interim report

Nonlinear optimal guidance algorithms for space mission

Quantification of Macroscopic Quantum Superpositions within Phase Space

Based on phase-space structures of quantum states, we propose a novel measure to quantify macroscopic quantum superpositions. Our measure simultaneously quantifies two different kinds of essential information for a given quantum state in a harmonious manner: the degree of quantum coherence and the effective size of the physical system that involves the superposition. It enjoys remarkably good analytical and algebraic properties. It turns out to be the most general and inclusive measure ever proposed that it can be applied to any types of multipartite states and mixed states represented in phase space.Comment: 4 pages, 1 figure, accepted for publication in Phys. Rev. Let

THE DETERMINANTS OF PARTICIPATION DECISION IN OFF-FARM WORK: THE IOWA CASE

This paper examines factors affecting the role of individual, farm production, family finance, and regional characteristics in affecting labor force decisions by farm households. Young, more educated households are much more likely to work off-farm, suggesting that off-farm labor has become an expected part of new farm households.Farm Management, Labor and Human Capital,

Supermassive black holes as the regulators of star formation in central galaxies

We present a relationship between the black hole mass, stellar mass, and star formation rate of a diverse group of 91 galaxies with dynamically-measured black hole masses. For our sample of galaxies with a variety of morphologies and other galactic properties, we find that the specific star formation rate is a smoothly decreasing function of the ratio between black hole mass and stellar mass, or what we call the specific black hole mass. In order to explain this relation, we propose a physical framework where the gradual suppression of a galaxy's star formation activity results from the adjustment to an increase in specific black hole mass and, accordingly, an increase in the amount of heating. From this framework, it follows that at least some galaxies with intermediate specific black hole masses are in a steady state of partial quiescence with intermediate specific star formation rates, implying that both transitioning and steady-state galaxies live within this region known as the "green valley." With respect to galaxy formation models, our results present an important diagnostic with which to test various prescriptions of black hole feedback and its effects on star formation activity.Comment: 15 pages, 4 figures, 2 tables. Accepted for publication in The Astrophysical Journa

Interplay of disorder and geometrical frustration in doped Gadolinium Gallium Garnet

The geometrically-frustrated, triangular antiferromagnet GGG exhibits a rich mix of short-range order and isolated quantum states. We investigate the effects of up to 1% Neodymium substitution for Gallium on the ac magnetic response at temperatures below 1 K in both the linear and nonlinear regimes. Substitutional disorder actually drives the system towards a more perfectly frustrated state, apparently compensating for the effect of imperfect Gadolinium/Gallium stoichiometry, while at the same time more closely demarcating the boundaries of isolated, coherent clusters composed of hundreds of spins. Optical measurements of the local Nd environment substantiate the picture of an increased frustration index with doping.Comment: 5 pages, 5 figure

Late osteoblast/early osteocyte-like cell line for visualizing collagen assembly in living cells [abstract]

Immortal cell lines representing the late osteoblast/early osteocyte phenotype have been generated that stably express a collagen-GFP or collagen-mCherry fusion protein to fluorescently label type I collagen fibrils either red or green. These novel cell lines allow visualization of collagen fibril assembly in living cells over time, which is not possible with existing technologies. The only other approaches that have been used for monitoring collagen assembly in living cells include using fluorescently labeled antibodies to collagen or a fluorescently labeled recombinant bacterial protein that binds to collagen. These have the disadvantage over our new invention that they may potentially interfere with the protein function and that they only label a population of fibrils at one point in time, which can then be followed (i.e. they do not necessarily label new collagen as it is synthesized). The specificity of the bacterial binding protein for type I collagen as opposed to other collagens is unclear and neither of these probes can be used to follow intracellular steps in the collagen assembly pathway, as they do not cross the cell membrane. Therefore our collagen-GFP and collagen-mCherry probes represent a significant improvement over existing technologies. Potential Areas of Applications: Potential commercial applications of this invention include using these cell lines to screen for drugs that enhance collagen assembly and could therefore have potential as bone anabolic treatments for diseases such as osteoporosis. The cells can also be used to screen for drugs that inhibit collagen assembly and therefore have potential as treatments to prevent fibrosis, etc. The cells also have many potential uses in developing approaches for tissue engineering of bone tissues. For example, the cells can be seeded onto scaffolds and the assembly of collagen can be monitored in real time in the living cultures. Mineral deposition on collagen can be monitored simultaneously using vital dyes for calcium deposition. These cell lines may also have commercial application for looking at mechanisms of tissue destruction, such as degradation of matrix proteins by proteases, such as occurs during inflammation

Chemical Abundance Study of One Red Giant Star in NGC 5694 : A Globular Cluster with Dwarf Spheroidals' Chemical Signature?

We report the abundance analysis of one red giant branch star in the metal-poor outer halo globular cluster NGC 5694. We obtain [Fe/H] = -1.93, based on the ionized lines, and our metallicity measurement is in good agreement with previous estimates. We find that [Ca+Ti/2Fe] and [Cu/Fe] of NGC 5694 are about 0.3 -- 0.4 dex lower than other globular clusters with similar metallicities, but similar to some LMC clusters and stars in some dwarf spheroidal galaxies. Differences persist, however, in the abundances of neutron capture elements. The unique chemical abundance pattern and the large Galactocentric distance (30 kpc) and radial velocity (-138.6 +/- 1.0 km/sec) indicate that NGC 5694 had an extragalactic origin.Comment: ApJL accepte