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C Appert

Publications and source records attributed to C Appert.

8 recordsLinked to original sources
PubMed2001

Boundary induced phase transitions in driven lattice gases with metastable states.

We study the effect of metastability onto boundary induced phase transitions in a driven lattice gas. The phase diagram for open systems, parameterized by the input and output rates, consists of two regions corresponding to the free flow and jammed phase. Both have been entirely characterized. The microscopic states in the high density phase are shown to have an interesting striped structure, which undergoes a coarsening process and survives in the thermodynamic limit.

Journal Article↗
PubMed2000

Large deviation function for the eden model and universality within the one-dimensional kardar-parisi-zhang class

It has been recently conjectured that for large systems, the shape of the central part of the large deviation function of the growth velocity would be universal for all the growth systems described by the Kardar-Parisi-Zhang equation in 1+1 dimension. One signature of this universality would be that the ratio of cumulants R(t)=[ (c)](2)/[ (c) (c)] would tend towards a universal value 0.415 17ellipsis as t tends to infinity, provided periodic boundary conditions are used. This has recently been questioned by Stauffer. In this paper we summarize various numerical and analytical results supporting this conjecture, and report in particular some numerical measurements of the ratio R(t) for the Eden model.

Journal Article↗
PubMed1994

Structural and catalytic properties of the four phenylalanine ammonia-lyase isoenzymes from parsley (Petroselinum crispum Nym.).

Near-full-length cDNAs for the four phenylalanine ammonia-lyase (PAL) isoenzymes in parsley (Petroselium crispum Nym.) were cloned and the complete amino acid sequences deduced. Fusion proteins with glutathione S-transferase were expressed in Escherichia coli, purified and cleaved. All of the resulting phenylalanine ammonia-lyase proteins, as well as the fusion proteins, were catalytically active. The turnover number of one selected isoenzyme, PAL-1, was estimated to be around 22 s-1 for each active site. In contrast to a certain degree of differential expression in various parts of parsley plants, the four phenylalanine ammonia-lyase isoenzymes exhibited very similar apparent Km values for L-phenylalanine (15-24.5 microM) as well as identical temperature (58 degrees C) and pH (8.5) optima. All of them were competitively inhibited by (E)-cinnamate with similar efficiency (Ki values: 9.1-21.5 microM), lacked cooperative behaviour, and accepted L-tyrosine as a substrate with low affinity (Km values: 2.6-7.8 mM). These results suggest that the occurrence of multiple gene copies has a function other than encoding isoenzymes with different enzyme kinetic properties.

Amino Acid Sequence↗