Victor W. Cheng

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Succinate dehydrogenase is an indispensable enzyme involved in the Krebs cycle as well as energy coupling in the mitochondria and certain prokaryotes. During catalysis, succinate oxidation is coupled to ubiquinone reduction by an electron transfer relay comprising a flavin adenine dinucleotide cofactor, three iron-sulfur clusters, and possibly a heme b556.(More)
In this paper, we propose a novel descriptor which characterizes an iris pattern with multi-scale step/ridge edge-type (ET) maps. The ET maps are determined with the derivative of Gaussian (DoG) and the Laplacian of Gaus-sian (LoG) filters. There are two major advantages of our approach. First, both the feature extraction and the pattern classification are(More)
In this paper the performance of diierent coding schemes for direct-sequence spread-spectrum (DS-SS) with multiple-access (MA) interference in a nonselective Rayleigh fading channel is considered. A conventional 64-ary orthogonal code (M 64) transmitting 6 bits of information is examined rst. Each of the 64 code symbols in the M 64 code is assumed to be(More)
Iron-sulfur ([Fe-S]) clusters are common in electron transfer proteins, and their midpoint potentials (E(m) values) play a major role in defining the rate at which electrons are shuttled. The E(m) values of [Fe-S] clusters are largely dependent on the protein environment as well as solvent accessibility. The electron transfer subunit (DmsB) of Escherichia(More)
Escherichia coli succinate dehydrogenase (Sdh) belongs to the highly conserved complex II family of enzymes that reduce ubiquinone. These enzymes do not generate a protonmotive force during catalysis and are electroneutral. Because of its electroneutrality, the quinone reduction reaction must consume cytoplasmic protons which are released stoichiometrically(More)