Reduced phospholipase A2 activity is not accompanied by reduced arachidonic acid release

Arachidonic acid release in cells highly over expressing cytosolic phospholipase A2 has been attributed to mitogen-activated protein kinase phosphorylation of cytosolic phospholipase A2 on serine-505. To investigate the role of cytosolic phospholipase A2 in cellular physiology, we attempted to inhibit cytosolic phospholipase A2 in the intact cell employing an antisense RNA strategy. Swiss 3T3 cells were stably transfected with an antisense cytosolic phospholipase A2 expression vector. A clone of cells with reduced immunodetectable cytosolic phospholipase A2, compared to a vector transfected cell line, was identified by Western blotting and a corresponding decrease in phospholipase A2 activity was confirmed by enzymatic assay in cell free extracts. However, arachidonic acid release from intact cells in response to agonists was not different between antisense and control cell lines. Thus, arachidonic acid release in intact cells with decreased cytosolic phospholipase A2 activity is likely to be modulated by rate limiting factors that are extrinsic to cytosolic phospholipase A2.

Low loading platinum nanoparticles on reduced graphene oxide-supported tungsten carbide crystallites as a highly active electrocatalyst for methanol oxidation

In this study, low loading platinum nanoparticles (Pt NPs) have been highly dispersed on reduced graphene oxide-supported WC nanocrystallites (Pt-WC/RGO) via program-controlled reduction-carburization technique and microwave-assisted method. The scanning electron microscopy and transmission electron microscopy results show that WC nanocrystallites are homogeneously decorated on RGO, and Pt NPs with a size of ca. 3 nm are dispersed on both RGO and WC. The prepared Pt-WC/RGO is used as an electrocatalyst for methanol oxidation reaction (MOR). Compared with the Pt/RGO, commercial carbon-supported Pt (Pt/C) and PtRu alloy (PtRu/C) electrocatalysts, the Pt-WC/RGO composites demonstrate higher electrochemical active surface area and excellent electrocatalytic activity toward the methanol oxidation, such as better tolerance toward CO, higher peak current density, lower onset potential and long-term stability, which could be attributed to the characterized RGO support, highly dispersed Pt NPs and WC nanocrystallites and the valid synergistic effect resulted from the increased interface between WC and Pt. The present work proves that Pt-WC/RGO composites could be a promising alternative catalyst for direct methanol fuel cells where WC plays the important role as a functional additive in preparing Pt-based catalysts because of its CO tolerance and lower price. 

Hard coatings on elastomers for reduced permeability and increased wear resistance

In this study, three different elastomers, namely hydrogenated nitrile butadiene rubber, fluoroelastomer and silicone, have been subjected to two different hard metallised coatings by ion implantation process. The three different elastomers are commonly used in various seal applications, where reduced wear and gas permeability are essential in maintaining seal performance and functionality. Samples of these rubbers have been coated with chromium coating in one set of tests. In the second set of tests, samples of elastomers have been coated with tungsten carbide coating being deposited on all the three different elastomers. Wear, gas permeability and mechanical behaviour of the coated samples were compared with each other and with the control uncoated elastomers. All the coated samples showed good reduction in gas permeability. With the use of metallised coatings, there has been improved resistance to wear in all the coated samples. Adhesion strength and effect of coating on the elastomer have been investigated by mechanical testing. Mechanical tests revealed good adhesion of metal coatings on all the rubber samples, and there was no detrimental effect on the mechanical properties after coating. © 2012 Institute of Materials, Minerals and Mining.

Generalized Langevin equation: An efficient approach to nonequilibrium molecular dynamics of open systems

The generalized Langevin equation (GLE) has been recently suggested to simulate the time evolution of classical solid and molecular systems when considering general nonequilibrium processes. In this approach, a part of the whole system (an open system), which interacts and exchanges energy with its dissipative environment, is studied. Because the GLE is derived by projecting out exactly the harmonic environment, the coupling to it is realistic, while the equations of motion are non-Markovian. Although the GLE formalism has already found promising applications, e. g., in nanotribology and as a powerful thermostat for equilibration in classical molecular dynamics simulations, efficient algorithms to solve the GLE for realistic memory kernels are highly nontrivial, especially if the memory kernels decay nonexponentially. This is due to the fact that one has to generate a colored noise and take account of the memory effects in a consistent manner. In this paper, we present a simple, yet efficient, algorithm for solving the GLE for practical memory kernels and we demonstrate its capability for the exactly solvable case of a harmonic oscillator coupled to a Debye bath.

External validation of the 2008 Framingham cardiovascular risk equation for CHD and stroke events in a European population of middle-aged men. The PRIME study

To test the applicability of the sex-specific 2008 Framingham general cardiovascular risk equation for coronary heart disease (CHD) and stroke in European middle-aged men from Ireland and France.

Material Logistics in Urban Construction Sites: A Structural Equation Model

Aim: The aim of this paper is to identify best practice relating to the effective management of materials in an urban, confined construction site, using structural equation modelling.

Methodology: A literature review, case study analysis and questionnaire survey are employed, with the results scrutinised using confirmatory factor analysis in the form of structural equation modelling.

Results: The following are the leading strategies in the management of materials in a confined urban site environment; (1) Consult and review the project programme, (2) Effective communication and delivery, (3) Implement site safety management plans, and (4) Proactive spatial monitoring and control.

Implication for Practice: With the relentless expansion of urban centres and the increasing high cost of materials, any potential savings made on-site would translate into significant monetary concessions on completion of a development.

Originality/Value: As on-site project management professionals successfully identify and implement the various strategies in the management of plant and materials on a confined urban site, successful resource management in this restrictive environment is attainable.

Innovative Aspect of Paper: An empirical study of three different construction sites in three different countries (Ireland, England and USA) together with a questionnaire survey from the industry, investigating the managerial strategies in the management of plant and material in confined urban site environments

SOLVING THE INHOMOGENEOUS SCHRODINGER-EQUATION ON A BIDIRECTIONAL PIPELINE OF TRANSPUTERS

In this paper we describe the design of a parallel solution of the inhomogeneous Schrodinger equation, which arises in the construction of continuum orbitals in the R-matrix theory of atomic continuum processes. A prototype system is described which has been programmed in occam2 and implemented on a bi-directional pipeline of transputers. Some timing results for the prototype system are presented, and the development of a full production system is discussed.

Mathematical anxiety is linked to reduced cognitive reflection: A potential road from discomfort in the mathematics classroom to susceptibility to biases

Background
When asked to solve mathematical problems, some people experience anxiety and threat, which can lead to impaired mathematical performance (Curr Dir Psychol Sci 11:181–185, 2002). The present studies investigated the link between mathematical anxiety and performance on the cognitive reflection test (CRT; J Econ Perspect 19:25–42, 2005). The CRT is a measure of a person’s ability to resist intuitive response tendencies, and it correlates strongly with important real-life outcomes, such as time preferences, risk-taking, and rational thinking.

Methods
In Experiments 1 and 2 the relationships between maths anxiety, mathematical knowledge/mathematical achievement, test anxiety and cognitive reflection were analysed using mediation analyses. Experiment 3 included a manipulation of working memory load. The effects of anxiety and working memory load were analysed using ANOVAs.

Results
Our experiments with university students (Experiments 1 and 3) and secondary school students (Experiment 2) demonstrated that mathematical anxiety was a significant predictor of cognitive reflection, even after controlling for the effects of general mathematical knowledge (in Experiment 1), school mathematical achievement (in Experiment 2) and test anxiety (in Experiments 1–3). Furthermore, Experiment 3 showed that mathematical anxiety and burdening working memory resources with a secondary task had similar effects on cognitive reflection.

Conclusions
Given earlier findings that showed a close link between cognitive reflection, unbiased decisions and rationality, our results suggest that mathematical anxiety might be negatively related to individuals’ ability to make advantageous choices and good decisions.

Advanced Ceramic Substrate with Ordered and Designed Micro-Structure for Applications in Automotive Catalysts

This study describes an innovative monolith structure designed for applications in automotive catalysis using an advanced manufacturing approach developed at Imperial College London. The production process combines extrusion with phase inversion of a ceramic-polymer-solvent mixture in order to design highly ordered substrate micro-structures that offer improvements in performance, including reduced PGM loading, reduced catalyst ageing and reduced backpressure.

This study compares the performance of the novel substrate for CO oxidation against commercially available 400 cpsi and 900 cpsi catalysts using gas concentrations and a flow rate equivalent to those experienced by a full catalyst brick when attached to a vehicle. Due to the novel micro-structure, no washcoat was required for the initial testing and 13 g/ft3 of Pd was deposited directly throughout the substrate structure in the absence of a washcoat.

Initial results for CO oxidation indicate that the advanced micro-structure leads to enhanced conversion efficiency. Despite an 79% reduction in metal loading and the absence of a washcoat, the novel substrate sample performs well, with a light-off temperature (LOT) only 15 °C higher than the commercial 400 cpsi sample.

To test the effects of catalyst ageing on light-off temperature, each sample was aged statically at a temperature of 1000 °C, based on the Bench Ageing Time (BAT) equation. The novel substrate performed impressively when compared to the commercial samples, with a variation in light-off temperature of only 3% after 80 equivalent hours of ageing, compared to 12% and 25% for the 400 cpsi and 900 cpsi monoliths, respectively.

Universal tight binding model for chemical reactions in solution and at surfaces. III. Stoichiometric and reduced surfaces of titania and the adsorption of water

We demonstrate a model for stoichiometric and reduced titanium dioxide intended for use in molecular dynamics and other atomistic simulations and based in the polarizable ion tight binding theory. This extends the model introduced in two previous papers from molecular and liquid applications into the solid state, thus completing the task of providing a comprehensive and unified scheme for studying chemical reactions, particularly aimed at problems in catalysis and electrochemistry. As before, experimental results are given priority over theoretical ones in selecting targets for model fitting, for which we used crystal parameters and band gaps of titania bulk polymorphs, rutile and anatase. The model is applied to six low index titania surfaces, with and without oxygen vacancies and adsorbed water molecules, both in dissociated and non-dissociated states. Finally, we present the results of molecular dynamics simulation of an anatase cluster with a number of adsorbed water molecules and discuss the role of edge and corner atoms of the cluster. (C) 2014 AIP Publishing LLC.

Experimental Autoimmune Uveoretinitis (EAU)-Related Tissue Damage and Angiogenesis Is Reduced in CCL2−/−CX3CR1gfp/gfp Mice

Purpose: To investigate the roles of the CCL2-CCR2 and CX3CL1-CX3CR1 pathways in experimental autoimmune uveoretinitis (EAU)-mediated retinal tissue damage and angiogenesis.

Methods: The C57BL/6J wild-type (WT) and CCL2−/−CX3CR1gfp/gfp (double knockout [DKO]) mice were immunized with IRBP1-20. Retinal inflammation and tissue damage were evaluated clinically and histologically at different days postimmunization (p.i.). Retinal neovascular membranes were evaluated by confocal microscopy of retinal flat mounts, and immune cell infiltration by flow cytometry.

Results: At day 25 p.i., DKO mice had lower clinical and histological scores and fewer CD45highCD11b+ infiltrating cells compared with WT mice. The F4/80+macrophages constitute 40% and 21% and CD11b+Gr-1+Ly6G+ neutrophils constitute 10% and 22% of retinal infiltrating cells in WT and DKO mice, respectively. At the late stages of EAU (day 60–90 p.i.), DKO and WT mice had similar levels of inflammatory score. However, less structural damage and reduced angiogenesis were detected in DKO mice. Neutrophils were rarely detected in the inflamed retina in both WT and DKO mice. Macrophages and myeloid-derived suppressor cells (MDSCs) accounted for 8% and 3% in DKO EAU retina, and 19% and 10% in WT EAU retina; 71% of infiltrating cells were T/B-lymphocytes in DKO EAU retina and 50% in WT EAU retina.

Conclusions: Experimental autoimmune uveoretinitis–mediated retinal tissue damage and angiogenesis is reduced in CCL2−/−CX3CR1gfp/gfp mice. Retinal inflammation is dominated by neutrophils at the acute stage and lymphocytes at the chronic stage in these mice. Our results suggest that CCR2+ and CX3CR1+monocytes are both involved in tissue damage and angiogenesis in EAU.