Values of games without side payments

A value forn-person games without side payments is given which coincides with theShapley value for games with side payments, and with theNash value for two-person games.     

Infrared spectra and molecular conformation of butyronitrile and methyl thioacetonitrile

The infrared absorption spectra of two related compounds, butyronitrile (CH₃CH₂-CH₂CN) and methylthioacetonitrile (CH₃SCH₂CN) have been examined in the liquid and solid phases. Vapour phase spectra of butyronitrile have also been recorded. Evidence is given for the existence of two rotational isomers trans and gauche, for both compounds. In both cases the energy difference between the two rotamers appears to be small with the gauche form identified as the low energy conformer for butyronitrile. For methylthioacetonitrile it was not possible to determine the more stable rotational isomer.     

Recent progress in biopolymer nanoparticle and microparticle formation by heat-treating electrostatic protein-polysaccharide complexes

Functional biopolymer nanoparticles or microparticles can be formed by heat treatment of globular protein-ionic polysaccharide electrostatic complexes under appropriate solution conditions. These biopolymer particles can be used as encapsulation and delivery systems, fat mimetics, lightening agents, or texture modifiers. This review highlights recent progress in the design and fabrication of biopolymer particles based on heating globular protein-ionic polysaccharide complexes above the thermal denaturation temperature of the proteins. The influence of biopolymer type, protein-polysaccharide ratio, pH, ionic strength, and thermal history on the characteristics of the biopolymer particles formed is reviewed. Our current understanding of the underlying physicochemical mechanisms of particle formation and properties is given. The information provided in this review should facilitate the rational design of biopolymer particles with specific physicochemical and functional attributes, as well as stimulate further research in identifying the physicochemical origin of particle formation.     

LV-pIN-KDEL: a novel lentiviral vector demonstrates the morphology,dynamics and continuity of the endoplasmic reticulum in live neurones

Background  

The neuronal endoplasmic reticulum (ER) is an extensive, complex endomembrane system, containing Ca²⁺ pumps, and Ca²⁺ channels that permit it to act as a dynamic calcium store. Currently, there is controversy over the continuity of the ER in neurones, how this intersects with calcium signalling and the possibility of physical compartmentalisation. Unfortunately, available probes of ER structure such as vital dyes are limited by their membrane specificity. The introduction of ER-targeted GFP plasmids has been a considerable step forward, but these are difficult to express in neurones through conventional transfection approaches. To circumvent such problems we have engineered a novel ER-targeted GFP construct, termed pIN-KDEL, into a 3^rd generation replication-defective, self-inactivating lentiviral vector system capable of mediating gene transduction in diverse dividing and post-mitotic mammalian cells, including neurones.     

Charge Site Mass Spectra: Conformation-Sensitive Components of the Electron Capture Dissociation Spectrum of a Protein

A conventional electron capture dissociation (ECD) spectrum of a protein is uniquely characteristic of the first dimension of its linear structure. This sequence information is indicated by summing the primary c ^m+ and z ^m+? products of cleavage at each of its molecular ion’s inter-residue bonds. For example, the ECD spectra of ubiquitin (M?+?nH)ⁿ⁺ ions, n?=?7–13, provide sequence characterization of 72 of its 75 cleavage sites from 1843 ions in seven c ^(1–7)+ and eight z ^(1–8)+? spectra and their respective complements. Now we find that each of these c/z spectra is itself composed of “charge site (CS)” spectra, the c ^m+ or z ^m+? products of electron capture at a specific protonated basic residue. This charge site has been H-bonded to multiple other residues, producing multiple precursor ion forms; ECD at these residues yields the multiple products of that CS spectrum. Closely similar CS spectra are often formed from a range of charge states of ubiquitin and KIX ions; this indicates a common secondary conformation, but not the conventional α-helicity postulated previously. CS spectra should provide new capabilities for comparing regional conformations of gaseous protein ions and delineating ECD fragmentation pathways.

Monte Carlo study of electron correlation functions for small molecules

A study is made of electron-electron correlation functions for use in trial wave functions for small molecules. New forms are proposed that have only a few variational parameters, and these parameters have physical meanings that are easily discerned. Total energies for H₂, LiH and Li₂ computed using these correlation functions are presented, and comparison is made with previous forms, including the Jastrow-Pade form often used in Monte Carlo studies. We further treat the possibility that correlation depends not only on the separation of a pair of electrons but also on the location of the electron pair relative to the nuclei — indicative of a density-dependent or many body correlation effect. Our results indicate that such a many-body correlation effect is weakly present.This work was supported by the Director, Office of Energy Research, Office of Basic Energy Sciences, Chemical Sciences Division of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098     

Tractable molecular theory of transport of Lennard-Jones fluids in nanopores

We present here a tractable theory of transport of simple fluids in cylindrical nanopores, which is applicable over a wide range of densities and pore sizes. In the Henry law low-density region the theory considers the trajectories of molecules oscillating between diffuse wall collisions, while at higher densities beyond this region the contribution from viscous flow becomes significant and is included through our recent approach utilizing a local average density model. The model is validated by means of equilibrium as well nonequilibrium molecular dynamics simulations of supercritical methane transport in cylindrical silica pores over a wide range of temperature, density, and pore size. The model for the Henry law region is exact and found to yield an excellent match with simulations at all conditions, including the single-file region of very small pore size where it is shown to provide the density-independent collective transport coefficient. It is also shown that in the absence of dispersive interactions the model reduces to the classical Knudsen result, but in the presence of such interactions the latter model drastically overpredicts the transport coefficient. For larger micropores beyond the single-file region the transport coefficient is reduced at high density because of intermolecular interactions and hindrance to particle crossings leading to a large decrease in surface slip that is not well represented by the model. However, for mesopores the transport coefficient increases monotonically with density, over the range studied, and is very well predicted by the theory, though at very high density the contribution from surface slip is slightly overpredicted. It is also seen that the concept of activated diffusion, commonly associated with diffusion in small pores, is fundamentally invalid for smooth pores, and the apparent activation energy is not simply related to the minimum pore potential or the adsorption energy as generally assumed.     

Synthesis and characterisation of phosphane-substituted Co3C clusters having a pendant allyl side-chain

Substituted μ₃-carbido-capped tricobalt carbonyl clusters have been synthesised by reaction of [Co₃(μ₃-C(O)OCH₂CHCH₂)(CO)₉] with a range of monodentate and chelating phosphane ligands. The products have been characterised by microanalysis, IR and NMR spectroscopy, mass spectrometry and, in the case of [Co₃(μ₃-CR)(CO)₇(dppe)], [Co₃(μ₃-CR)(CO)₇(dppm)], [Co₃(μ₃-CR)(CO)₇(PPh₃)₂], [Co₃(μ₃-CR)(CO)₇(PMe₃)₂] and [Co₃(μ₃-CR)(CO)₆(PEt₃)₃] (R=C(O)OCH₂CHCH₂), single crystal X-ray diffraction.