Recent Results on the Decay of Metastable Phases

We review some aspects of current knowledge regarding the decay of metastable phases in many-particle systems. In particular we emphasize recent theoretical and computational developments and numerical results regarding homogeneous nucleation and growth in kinetic Ising and lattice-gas models. An introductory discussion of the droplet theory of homogeneous nucleation is followed by a discussion of Monte Carlo and transfer-matrix methods commonly used for numerical study of metastable decay, including some new algorithms. Next we discuss specific classes of systems. These include a brief discussion of recent progress for fluids, and more exhaustive considerations of ferromagnetic Ising models ({\it i.e.}, attractive lattice-gas models) with weak long-range interactions and with short-range interactions. Whereas weak-long-range-force (WLRF) models have infinitely long-lived metastable phases in the infinite-range limit, metastable phases in short-range-force (SRF) models eventually decay, albeit extremely slowly. Recent results on the finite-size scaling of metastable lifetimes in SRF models are reviewed, and it is pointed out that such effects may be experimentally observable.Comment: 34 pages, LaTex, 8 ps figs. on request, preprint FSU-SCRI-94-6

Research Notes : United States : Superoxide dismutase (SOD) and tetrazolium oxidase (TO) zymograms observed in gradient PAGE gels and preliminary inheritance data for type 3 zymograms

We tested gradient PAGE gels for their ability to resolve isozymes with a specific SOD (EC 1.15.1.1) stain as well as with a nonspecific TO stain. In particular, we wanted to test gradient gels for use in scoring F2 seeds segregating for the cultivar-specific type 1 and type 3 TO zymogram patterns first reported by Gorman and Kiang (1977). TO electrophoretic bands are caused by any number of enzymes (particularly SOD) that prevent the spontaneous reduction of tetrazolium dyes in the electron-transfer staining systems used to detect dehydrogenases

Relaxation dynamics of the toric code in contact with a thermal reservoir: Finite-size scaling in a low temperature regime

We present an analysis of the relaxation dynamics of finite-size topological qubits in contact with a thermal bath. Using a continuous-time Monte Carlo method, we explicitly compute the low-temperature nonequilibrium dynamics of the toric code on finite lattices. In contrast to the size-independent bound predicted for the toric code in the thermodynamic limit, we identify a low-temperature regime on finite lattices below a size-dependent crossover temperature with nontrivial finite-size and temperature scaling of the relaxation time. We demonstrate how this nontrivial finite-size scaling is governed by the scaling of topologically nontrivial two-dimensional classical random walks. The transition out of this low-temperature regime defines a dynamical finite-size crossover temperature that scales inversely with the log of the system size, in agreement with a crossover temperature defined from equilibrium properties. We find that both the finite-size and finite-temperature scaling are stronger in the low-temperature regime than above the crossover temperature. Since this finite-temperature scaling competes with the scaling of the robustness to unitary perturbations, this analysis may elucidate the scaling of memory lifetimes of possible physical realizations of topological qubits.Comment: 14 Pages, 13 figure

Research Notes : United States : Soybean amylase zymograms on gradient PAGE gels

There have been numerous papers dealing with amylase isozymes in soybeans (i.e., Morita and Yagi, 1979; Hildebrand and Hymowitz, 1980; Kiang, 1981; Adams et al., 1981; Mikami et al., 1982). All have reported beta-amylase as the predominant amylase type in most soybean lines and that varietal differences in beta-amylase either for electrophoretic mobility, pl, or enzyme activity were observed. Gorman and Kiang (1978), Hildebrand and Hymowitz (1980), Kiang (1981), and Griffin and Palmer (1986) reported similar results concerning the inheritance of different beta-amylase electrophoretic variants (i.e., variants were the result of five different alleles at the Spl locus)

Research Notes: Amylase and acid phosphatase genotypes of Glycine max, Glycine soja and Neonotonia wightii

Three amylase loci, Am-1, Am-2 , and Am-3, have been identified by electrophoresis (Gorman and Kiang , 1978) . The activity of amylase at Am-1 and Am-2 is very weak, and that at Am-3 is much str onger. Based on heat lability and chemical reaction, Reiss (1978) concluded Am-1 and Am- 2 represent α - amylase and Am-3 β-amylase

Research Notes : United States : Linkage of electrophoretic loci

In our studies of the inheritance of various electrophoretic variants, we have examined F2 segregation data from many crosses (see Gorman, 1983, for a listing). Many of these crosses were segregating for multiple loci, allowing linkage data to be collected. Table 1 represents a sunnnary of the linkage patterns we have observed between the listed electrophoretic loci (see Gorman and Kiang, 1978; Kiang, 1981; Gorman et al., 1983, concerning the establishment of these loci)

Research Notes : United States : Inheritance of a second leucine amino-peptidase locus and tests of its linkage with other loci

In dry soybean seed, only one leucine amino peptidase (LAP) anodal band was observed by acrylamide slab gel electrophoresis (Gorman et al., 1983). This band gradually declined in intensity and disappeared in all tissues about 10-12 days after germination. Three mobility variants (Rf\u27s 0.59, 0.53,and 0.58) were observed in the band, which was controlled by a single locus (Gor-man et al., 1983; Kiang and Gorman, 1983; Gorman, 1983)

Scenarios of domain pattern formation in a reaction-diffusion system

We performed an extensive numerical study of a two-dimensional reaction-diffusion system of the activator-inhibitor type in which domain patterns can form. We showed that both multidomain and labyrinthine patterns may form spontaneously as a result of Turing instability. In the stable homogeneous system with the fast inhibitor one can excite both localized and extended patterns by applying a localized stimulus. Depending on the parameters and the excitation level of the system stripes, spots, wriggled stripes, or labyrinthine patterns form. The labyrinthine patterns may be both connected and disconnected. In the the stable homogeneous system with the slow inhibitor one can excite self-replicating spots, breathing patterns, autowaves and turbulence. The parameter regions in which different types of patterns are realized are explained on the basis of the asymptotic theory of instabilities for patterns with sharp interfaces developed by us in Phys. Rev. E. 53, 3101 (1996). The dynamics of the patterns observed in our simulations is very similar to that of the patterns forming in the ferrocyanide-iodate-sulfite reaction.Comment: 15 pages (REVTeX), 15 figures (postscript and gif), submitted to Phys. Rev.

Near-field optical spectroscopy and microscopy of self-assembled GaN∕AlN nanostructures

The spatial distribution and emission properties of small clusters of GaNquantum dots in an AlN matrix are studied using high-resolution electron and optical microscopy. High-resolution transmission electron microscopy reveals near vertical correlation among the GaNdots due to a sufficiently thin AlN spacer layer thickness, which allows strain induced stacking. Scanning electron and atomic force microscopy show lateral coupling due to a surface roughness of ∼50–60nm. Near-field photoluminescence in the illumination mode (both spatially and spectrally resolved) at 10K revealed emission from individual dots, which exhibits size distribution of GaNdots from localized sites in the stacked nanostructure. Strong spatial localization of the excitons is observed in GaNquantum dots formed at the tip of self-assembled hexagonal pyramid shapes with six [101¯1¯] facets

Aboriginal Rules: The Black History of Australian Football

This paper is interested in the significance of Australian football to the Aboriginal and Torres Strait Islander people of Australia. In particular, this paper is interested in the cultural power of football and how it has foregrounded the struggle and highlighted the contribution that Indigenous people have made to the national football code of Australia. This paper also discusses key moments in Indigenous football history in Australia. It questions further that a greater understanding of this contribution needs to be more fully explored from a national perspective in order to appreciate Indigenous peoples' contribution to the sport not just in elite competitions but also at a community and grass roots level