Group signature

ChHe91 David Chaum, Eugene van Heijst Group signatures Eurocrypt 91, LNCS 547, Springer-Verlag, Berlin 1991, 257-265. 

ChPe95 Lidong Chen, Torben P. Pedersen New Group Signature Schemes Eurocrypt 94, LNCS 950, Springer-Verlag, Berlin 1995,171-181. 

Senior managers generally respond better to specific requests than to broad expressions of need. "First we need a mission statement" is likely to draw a quizzical expression and limited assistance. "The task group has developed this mission statement for your review and signature we plan to distribute it to all plant locations to kick off the effort" tells the boss exactly what you need and why you need it, and establishes that you expect to carry the ball. 

Ghosts are caused when two or more frequency components couple, or merge, to form another discrete frequency component in the vibration signature. This generally occurs with multiple-speed machines or a group of single-speed machines. 

Cytochrome P450 monooxygenases are characterized through the presence of the heme (protoporphyrin IX) prosthetic group (Scheme 10.1) that is coordinated to the enzyme through a conserved cysteine ligand. They have obtained their name from the signature absorption band with a maximum near 450 nm in the difference spectrum when incubated with CO. The absorption arises from the Soret Jilt transition of the ferrous protoporphyrin IX-CO complex. 

OHads formation has a clear voltammetric signature on a number of surfaces, including the (lll)-oriented surfaces of platinum group metals, Pt(lll) in alkaline and acid electrolytes of non-adsorbing anions [Markovic and Ross, 2002], and Au(lll), Au(lOO), and Ag(lll) in neutral and alkaline electrolytes [Savinova et al., 2002]. On these surfaces, the reaction has a reversible character. Anderson and co-workers calculated the reversible potential of Reaction (9.1) on Pt to be 0.62 V with respect to a reversible hydrogen electrode (RHE) [Anderson, 2002]. The Pt(lll)-OH bond energy has been estimated to be about 1.4 eV in an alkaline electrolyte [Markovic and Ross, 2002]. 

Further work by Trost established the involvement of metallacarbenoid species.292,293 A dimer product 307, incorporating a cyclopropyl group, was observed in the reaction of 304 in the presence of the highly electron-deficient palladole catalyst 305 (Scheme 78). This transformation is the signature of an intermediate of type 306. This chemistry could be rendered useful by playing with other unsaturated bonds as the carbene acceptor, and a variety of polycyclic adducts such as 308 could be synthesized. 

Amyloid fibrils form from a variety of native proteins with diverse sequences and folds. The classic method for the structural analysis of amyloid has been X-ray fiber diffraction amyloid fibrils exhibit a characteristic diffraction signature, called the cross-/) pattern. This cross-/ pattern suggested a repeating structure in which /1-sheets run parallel to the fiber axis with their constituent /1-strands perpendicular to that direction (Sunde and Blake, 1997). This diffraction signature pointed to an underlying common core molecular structure for the amyloid fibril that could accommodate diverse sequences and folds. A number of groups have proposed amyloid folds that are consistent with the experimental data and these can be linked to repeating /1-structured units. 

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