Sensitivity of decisions with imprecise utility trade-off parameters using boundary linear utility

In earlier work we have developed methods for analysing decision problems based on multi-attribute utility hierarchies, structured by mutual utility independence, which are not precisely specified due to unwillingness or inability of an individual or group to agree on precise values for the trade-offs between the various attributes. Our analysis is based on whatever limited collection of preferences we may assert between attribute collections. In this paper we introduce three methods to assess the robustness of our selected decision. Two of these use the metric generated by the weights of the boundary linear utility. The third applies directly to the space of trade-off parameters.     

Interactions between carriers and LO phonons in bulk p-GaSb and p-InSb: Raman interference lineshapes

Coherent interaction between single-particle excitations of carriers located near Γ and large wavevector LO phonons results in a Fanotype Raman lineshape when the incident photon energy is resonant with the E₁ or E₁ + Δ₁ energy gaps of heavily doped p-GaSb and p-InSb. The present results are simpler to interpret than our previous data on lightly doped samples which involve interactions between carriers confined within the surface accumulation layer and extended bulk phonons.     

Epitope Targeting of Tertiary Protein Structure Enables Target‐Guided Synthesis of a Potent In‐Cell Inhibitor of Botulinum Neurotoxin

Botulinum neurotoxin (BoNT) serotype A is the most lethal known toxin and has an occluded structure, which prevents direct inhibition of its active site before it enters the cytosol. Target‐guided synthesis by in situ click chemistry is combined with synthetic epitope targeting to exploit the tertiary structure of the BoNT protein as a landscape for assembling a competitive inhibitor. A substrate‐mimicking peptide macrocycle is used as a direct inhibitor of BoNT. An epitope‐targeting in situ click screen is utilized to identify a second peptide macrocycle ligand that binds to an epitope that, in the folded BoNT structure, is active‐site‐adjacent. A second in situ click screen identifies a molecular bridge between the two macrocycles. The resulting divalent inhibitor exhibits an in vitro inhibition constant of 165 pM against the BoNT/A catalytic chain. The inhibitor is carried into cells by the intact holotoxin, and demonstrates protection and rescue of BoNT intoxication in a human neuron model.     

Characteristics of the combustion water of organically bound tritium (OBT) measurements of fish samples

Improving accuracy and precision of measurements of organically bound tritium (OBT) activity concentration in environmental samples has become a key aspect of the study of radiological effects by scientists and regulators. Significant quenching effects are known to occur in the measurement of fish samples for OBT using a liquid scintillation counter. In this study, the quench effects of fish and vegetable samples were investigated, as well as the ionic composition of the samples following combustion, neutralization and distillation processes. Furthermore, revised water equivalent factors of various foodstuffs for OBT measurement were calculated using the Health Canada database.

     

Hepatitis C virus NS3 protease requires its NS4A cofactor peptide for optimal binding of a boronic acid inhibitor as shown by NMR

NMR spectroscopy was used to characterize the hepatitis C virus (HCV) NS3 protease in a complex with the 24 residue peptide cofactor from NS4A and a boronic acid inhibitor, Ac-Asp-Glu-Val-Val-Pro-boroAlg-OH. Secondary-structure information, NOE constraints between protease and cofactor, and hydrogen-deuterium exchange rates revealed that the cofactor was an integral strand in the N-terminal beta-sheet of the complex as observed in X-ray crystal structures. Based upon chemical-shift perturbations, inhibitor-protein NOEs, and the protonation state of the catalytic histidine, the boronic acid inhibitor was bound in the substrate binding site as a transition state mimic. In the absence of cofactor, the inhibitor had a lower affinity for the protease. Although the inhibitor binds in the same location, differences were observed at the catalytic site of the protease.     

Ultrasonic absorption in aqueous salts of the lanthanides. IV. Sulfates in D2O

The rates of formation of the monosulfate complexes of the trivalent rare earth ions of Pr, Sm, Gd, and Dy have been measured at 25°C in D₂O and additional measurements made on Pr, Sm, Gd, Tb, and Ho in water. Using formation constants recently calculated from conductance measurements in D₂O, the rate data were compared to our reevaluated data in water to establish if a solvent isotope effect was present, which may contribute to our understanding of the mechanism of complexation. Contrary to previous reports, none is observed, the rate constants being in agreement within experimental error and within the limits of the assumptions used in the mathematical interpretation. Evidence therefore points to a dissociative mechanism in which the rate of exchange of the solvent from the primary hydration sphere of the cation is rate-determining.     

Response functions for dimers and square-symmetric molecules in four-wave-mixing experiments with polarized light

Four-wave-mixing nonlinear-response functions are given for intermolecular and intramolecular vibrations of a perpendicular dimer and intramolecular vibrations of a square-symmetric molecule containing a doubly degenerate state. A two-dimensional particle-in-a-box model is used to approximate the electronic wave functions and obtain harmonic potentials for nuclear motion. Vibronic interactions due to symmetry-lowering distortions along Jahn-Teller active normal modes are discussed. Electronic dephasing due to nuclear motion along both symmetric and asymmetric normal modes is included in these response functions, but population transfer between states is not. As an illustration, these response functions are used to predict the pump-probe polarization anisotropy in the limit of impulsive excitation.