Structure of Metastable States in Phase Transitions with High-Spin Low-Spin Degree of Freedom

Difference of degeneracy of the low-spin (LS) and high-spin (HS) states causes interesting entropy effects on spin-crossover phase transitions and charge transfer phase transitions in materials composed of the spin-crossover atoms. Mechanisms of the spin-crossover (SC) phase transitions have been studied by using Wajnflasz model, where the degeneracy of the spin states (HS or LS) is taken into account and cooperative natures of the spin-crossover phase transitions have been well described. Recently, a charge transfer (CT) phase transition due to electron hopping between LS and HS sites has been studied by using a generalized Wajnflasz model. In the both systems of SC and CT, the systems have a high temperature structure (HT) and a low temperature structure (LT), and the change between them can be a smooth crossover or a discontinuous first order phase transition depending on the parameters of the systems. Although apparently the standard SC system and the CT system are very different, it is shown that both models are equivalent under a certain transformation of variables. In both systems, the structure of metastable state at low temperatures is a matter of interest. We study temperature dependence of fraction of HT systematically in a unified model, and find several structures of equilibrium and metastable states of the model as functions of system parameters. In particular, we find a reentrant type metastable branch of HT in a low temperature region, which would play an important role to study the photo-irradiated processes of related materials.Comment: 19 pages, 11 figure

Mitochondrial Genome Polymorphism in Lolium perenne

The restriction fragment length polymorphisms (RFLPs) of mitochondrial DNA (mtDNA) of perennial ryegrass (Lolium perenne L.) were investigated to elucidate the genetic relatedness among the 128 cultivars including diploid and tetraploid. Many patterns of RFLPs were observed and allowed assigning of the cultivars into the main eight haplotypes of mitochondrial genome relatedness. The American cultivars were classified into haplotype I and VIII which were remote at the mitochondrial genome from each other, the European ones were distributed to all haplotypes and the tetraploid ones were mostly assigned into the haplotype V. The assessment of mtDNA RFLPs may be a valuable method in analyzing a cytoplasmic differentiation among the perennial ryegrass cultivars. Further investigations are required to elucidate mtDNA diversity in relation with the maternal effects on the agronomic traits of perennial ryegrass

Robust, Conducting, and Transparent Polymer Composites using Surface-Modified and Individualized Double-Walled Carbon Nanotubes

This is the pre-peer reviewed version of the following article: ADVANCED MATERIALS. 20(23):4509-4512 (2008), which has been published in final form at 10.1002/adma.200801659.ArticleADVANCED MATERIALS. 20(23):4509-4512 (2008)journal articl

Raman study on electrochemical lithium insertion into multiwalled carbon nanotubes

This is the pre-peer reviewed version of the following article: JOURNAL OF RAMAN SPECTROSCOPY 39(9): 1183-1188, 2008, which has been published in final form http://www3.interscience.wiley.com/journal/118639317/abstract.ArticleJOURNAL OF RAMAN SPECTROSCOPY. 39(9): 1183-1188 (2008)journal articl

Monitoring tree growth and phenology in restored forests.

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Asymptomatic Intramammary Infection with Multidrug-Resistant Gram-Negative Bacteria in a Research Dairy Farm : Incidence and Genetic Basis of Resistance

Nonpathogenic and opportunistic bacteria are increasingly recognized as reservoirs of antibiotic resistance genes. However, nothing is known about the mechanisms of antibiotic resistance in such bacteria isolated from the udders of healthy animals. In this study, 150 Gram-negative strains isolated from milk samples of healthy dairy cows were screened for the presence of a large pool of antibiotic resistance markers. Strains carrying β-lactamase-resistance genes, including SHV-1, SHV-11, SHV-27, TEM-1, OXY-1, CTX-M-2 and class 1 integrons, were detected. Our findings give the first evidence that nonpathogenic and opportunistic bacteria carrying antibiotic resistance genes can asymptomatically invade healthy udders and suggest that they may play a role in the dissemination of antibiotic resistance genes to the other udder pathogens