Qualitative operators for reasoning maps: Evaluating multi-criteria options with networks of reasons

Cognitive/causal maps have been widely used as a powerful way of capturing decision-makers’ views about a problem, representing it as a cause–effect discourse. Several ways of making causal inferences from this type of model have been proposed in the Operational Research and Artificial Intelligence literatures, but none, as far as we are aware, has attempted to use a causal map structure to perform a multi-criteria evaluation of decision alternatives. Recently, we have proposed a new multi-criteria method, denominated as a Reasoning Map, which permits the use of decision-makers’ reasoning, structured as a network of means-and-ends (a particular type of causal map) to perform such an evaluation. In this manner, the model resembles the way that people talk and think about decisions in practice. The method also pays explicit attention to the cognitive limitations of decision-makers in providing preference information. Thus it employs qualitative assessment of preferences, utilises aggregation operators for qualitative data and provides also qualitative outputs. In this paper we discuss and evaluate possible ways of aggregating qualitative performance information in Reasoning Maps.     

Ultrasonic wave propagation in concentrated slurries – The modelling problem

The suspended particle size distribution in slurries can, in principle, be estimated from measured ultrasonic wave attenuation across a frequency band in the 10s of MHz range. The procedure requires a computational model of wave propagation which incorporates scattering phenomena. These models fail at high particle concentrations due to hydrodynamic effects which they do not incorporate. This work seeks an effective viscosity and density for the medium surrounding the particles, which would enable the scattering model predictions to match experimental data for high solids loading. It is found that the required viscosity model has unphysical characteristics leading to the conclusion that a simple effective medium modification to the ECAH/LB is not possible. The paper confirms the successful results which can be obtained using core–shell scattering models, for smaller particles than had previously been studied, and outlines modifications to these which would permit rapid computation of sufficient stability to support fast particle sizing procedures.     

Lipid metabolite profiling identifies desmosterol metabolism as a new antiviral target for hepatitis C virus

Hepatitis C virus (HCV) infection has been clinically associated with serum lipid abnormalities, yet our understanding of the effects of HCV on host lipid metabolism and conversely the function of individual lipids in HCV replication remains incomplete. Using liquid chromatography-mass spectrometry metabolite profiling of the HCV JFH1 cell culture infection model, we identified a significant steady-state accumulation of desmosterol, an immediate precursor to cholesterol. Pharmacological inhibition or RNAi-mediated depletion of DHCR7 significantly reduced steady-state HCV protein expression and viral genomic RNA. Moreover, this effect was reversed when cultures were supplemented with exogenous desmosterol. Together, these observations suggest an intimate connection between HCV replication and desmosterol homeostasis and that the enzymes responsible for synthesis of desmosterol may be novel targets for antiviral design.     

Competing Effects of Chlorination on the Strength of Te⋅⋅⋅O Chalcogen Bonds Select the Structure of Mixed Supramolecular Macrocyclic Aggregates of Iso-Tellurazole N-Oxides

Chlorination of 3-methyl-5-phenyl-1,2-tellurazole-2-oxide yielded the λ⁴Te dichloro derivative. Its crystal structure demonstrates that the heterocycle retains its ability to autoassociate by chalcogen bonding (ChB) forming macrocyclic tetramers. The corresponding Te⋅⋅⋅O ChB distances are 2.062 Å, the shortest observed to date in aggregates of this type. DFT−D3 calculations indicate that while the halogenated molecule is stronger as a ChB donor it also is a weaker ChB acceptor; the overall effect is that the ChBs in the chlorinated homotetramer are not significantly stronger. However, partial halogenation or scrambling selectively yield the 2 : 2 heterotetramer with alternating λ⁴Te and λ²Te centers, which calculations identified as the thermodynamically preferred arrangement.     

Abnormally slow reaction of oppositely charged ions: The kinetics of dopamine hydrochloride oxidation by ammonium peroxydisulfate

The kinetic curves for oxidation of dopamine hydrochloride in aqueous solution in the presence of ammonium peroxydisulfate were obtained by UV–vis spectroscopy and potentiometry. It was shown that the reaction follows the first-order kinetic equation and proceeds at a low rate. The values for the activation energy and the preexponential factor were determined as 75 kJ × mol⁻¹ and 4 × 10⁸ s⁻¹, respectively. The activation entropy was found having a negative value of −89 J × mol⁻¹ × K⁻¹. The first reaction order, the low preexponential factor and the negative activation entropy value for the reaction between the 2-(3,4-dihydroxyphenyl)ethanammonium cation and the peroxydisulfate anion were explained by the formation of ionic associates, which slowly enter into the internal redox reaction.     

GIT-equivalence and semi-stable subcategories of quiver representations

In this paper, we answer the question of when the subcategory of semi-stable representations is the same for two rational vectors for an acyclic quiver. This question has been previously answered by Ingalls, Paquette, and Thomas in the tame case in [14]. Here we take a more invariant theoretic approach, to answer this question in general. We recover the known result in the tame case.     

The Use of a Simple Multiple-Criteria Model to Assist in Selection from a Shortlist

The use of a simple multiple-criteria model to assist in decision making is described. The model, a hierarchical additive weighted value-function, was used as a part of a decision-making process to select, from a shortlist of three, the company with which to place a contract for the development of a computerized financial management system. The multiple-criteria model and its use are described in detail. To conclude, there is a discussion on the contribution of the model to the decision-making process as perceived by the decision-making group.     

Acylmethanesulfonamides as new acylating agents for primary amines

A new, simple and efficient procedure for the preparation of secondary amides through internal condensation of acylmethanesulfonamides ammonium salts is described. The selective acylation of mixed primary-secondary amines could be an attractive application of the new method.