Mutual enhancement: Toward an understanding of the collective preference for shared information.

Groups tend to discuss and repeat information known by all members (shared) more than they do information known by one member (unshared). One factor that may influence this effect is the tendency for members to positively evaluate one another when mentioning shared information. Three experiments demonstrated this "mutual enhancement" effect. Experiment 1 showed that mutual enhancement was related to participants' and their partners' exchanging the same pieces of information. Experiment 2 illustrated that mutual enhancement was not related to the extent that participants liked partners or saw them as having similar opinions. Experiment 3 showed mutual enhancement in face-to-face dyads that discussed shared information. A combined analysis across the 3 experiments showed the robustness of mutual enhancement. Implications of mutual enhancement for group discussion are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rapid Determination of Bitterness in Beer Using Fluorescence Spectroscopy and Chemometrics

Two fluorescence spectroscopic methods with the aim to develop a fast quantitative determination of bitterness in beer were tested. The first method was based on autofluorescence of the diluted and degassed beer samples without any further processing. A total of 21 dark and light beer samples were analyzed and multivariate Partial Least Squares (PLS) regression models to bitterness in form of international bitter units (IBU) were performed. A prediction error in the form of Root Mean Square Error of Cross‐Validation (RMSECV) of 2.77 IBU was obtained using six PLS components. Focusing only on the light beer samples the RMSECV was reduced to 1.81 IBU. The second method developed was based on addition of europium to induce delayed fluorescence signals in the beer samples. PLS models yielded an RMSECV of 2.65 IBU for all beers, while a model on the light beer samples gave an RMSECV of 1.75 IBU. The obtained prediction errors were compared to the errors given in the literature for the traditional extraction method of determining IBU.     

Preliminary examination of tobacco withdrawal in adolescent smokers during smoking cessation treatment

Tobacco withdrawal symptoms have been shown to play a significant role in mediating relapse to smoking in adult smokers; however, few prospective studies have examined the course of tobacco withdrawal symptoms over time and their connection to lapse in adolescent smokers. Withdrawal symptoms were assessed weekly for 4 weeks in a sample of adolescent smokers participating in a pilot cessation intervention. Adolescent smokers experienced an exacerbation in overall withdrawal symptoms, particularly of cravings and restlessness, although symptoms were generally mild. The course of symptoms was different for boys and girls: Girls generally experienced a peak and subsequent decline in symptoms early in the establishment of abstinence, whereas boys experienced a constant level of symptoms that did not decline over the 4 weeks. Finally, withdrawal symptoms experienced on quit day were not related to lapse to smoking during the course of treatment for either boys or girls. These results suggest that although withdrawal symptoms may be uncomfortable, they may not be the most salient to a lapse to smoking for adolescent smokers attempting to quit. These findings have direct implications for the design and implementation of treatment of nicotine dependence in adolescent smokers.     

VEGF‐Functionalized Polyelectrolyte Multilayers as Proangiogenic Prosthetic Coatings

Stimulation of transprosthetic vascularization represents an interesting strategy in implantology to allow rapid tissue integration and finally to avoid prosthetic rejection. To achieve this goal, we modified the surface of porous titanium implants with polyelectrolyte multilayer (PEM) films functionalized with vascular endothelial growth factor (VEGF). Among the two PEM systems investigated, poly(L‐lysine)/poly(L‐glutamic acid) (PLL/PGA) and poly(allylamine hydrochloride)/poly(sodium 4‐styrenesulfonate) (PAH/PSS), the (PAH/PSS)₄ architecture was selected to functionalize porous titanium, both for its high efficiency to adsorb VEGF and for its biocompatibility toward endothelial cells. In an original way, we unambiguously demonstrated that VEGF adsorbed on (PAH/PSS)₄ maintains its bioactivity in vitro and stimulates endothelial cells proliferation. This effect was correlated with specific activation of intracellular signaling pathways induced by successive phosphorylation of the endothelial VEGF receptor VEGFR2 and mitogen‐activated protein kinases (MAPK) ERK1/2. By clearly demonstrating the proangiogenic activity of the VEGF‐PEM coating in vitro, the present study constitutes a first step toward in vivo application.     

Does demolition or refurbishment of old and inefficient homes help to increase our environmental,social and economic viability?

The issue of whether to demolish or refurbish older housing has been debated for over a century. It has been an active policy area since the late 1880s, when the Government first authorised the statutory demolition of insanitary slums. In the 1960s, revulsion at the scale of ‘demolition blight’ and new building caused a rethink, leading to a major reinvestment in inner city neighbourhoods of older housing. In the past 5 years, debate on demolition and new building has been intensified by the Government's Sustainable Communities Plan of 2003, with its proposals for large-scale clearance and building. Environmental arguments about renovating the existing stock have gained increasing prominence as people have sought to defend their communities from demolition.     

Hydrophilic and hydrophobic copolymers of a polyaspartylhydrazide bearing positive charges as vector for gene therapy

BACKGROUND: The design of polymeric vectors for gene delivery provided with specific properties is one of the most critical aspects for a successful gene therapy. These polymers should be biocompatible as well as able to carry efficiently DNA to target tissues and to transfect it into cells. RESULTS: The formation of complexes of poly[(α,β‐asparthylhydrazide)–poly(ethylene glycol)] and poly[(α,β‐asparthylhydrazide)–hexadecylamine] copolymers functionalised with glycidyltrimethylammonium chloride (PAHy–PEG‐GTA and PAHy–C₁₆‐GTA, respectively) with DNA was studied. The effects of the introduction of hydrophilic (PEG) or hydrophobic (C₁₆) moieties on the chains of PAHy–GTA copolymers, such as the stabilising effect on the DNA structure, were evaluated. In particular, we observed a high DNA protection by PAHy–PEG‐GTA copolymers. Degradation studies led us to suppose a particular aqueous conformation of the polyionic complex of PAHy–PEG₂₀₀₀‐GTA in which DNA should be internalised into an inner core surrounded by a PEG hydrophilic shell; while no significant protection was detected with PAHy–C₁₆‐GTA in which DNA should be disposed on the surface of the complex, freely exposed to DNase II action. CONCLUSION: The insertion of PEG or C₁₆ chains into the polymeric structure of PAHy–GTA copolymers changes significantly the DNA complexing and protecting ability of the PAHy–GTA copolymers, showing that hydrophilic and hydrophobic side chains can play a crucial role in supramolecular arrangements of interpolyelectrolyte complexes between DNA and PAHy copolymers. Copyright © 2008 Society of Chemical Industry     

Photocatalytic degradation of imidazolinone fungicide in TiO2-coated optical fiber reactor

The photocatalytic degradation of the fungicide fenamidone is studied in a TiO₂-coated optical fiber photoreactor. Fenamidone is slowly transformed with a kinetic order of 1 and a degradation rate of 0.02 h⁻¹. Intermediate products were isolated and identified by means of solid phase extraction (SPE) coupled to liquid chromatography-mass spectrometry techniques (LC-MS). A proposed degradation pathway of fenamidone is presented, involving mainly hydroxylation and oxidation reactions. Carboxylic acids and sulfate ions resulting from the same reaction in a powder reactor were also identified.     

Experimental characterization of the flow pattern in an annular fluidized bed

The annular fluidized bed combines a long solids residence time and a good heat and mass transfer. To experimentally characterize the flow pattern in the system, pressure drop and capacitance probe measurements have been carried out under ambient conditions in two plants of inner diameters of 0.19 and 0.74 m. Depending on the interaction between gas velocity in the central jet and ratio of bubble to central nozzle diameter, the ratio of internal to external solids circulation can be regulated.     

The role of iron in the prevention of nickel electrode deactivation in alkaline electrolysis

There is some uncertainty concerning the role of iron deposits on the surface of nickel electrodes with respect to electrode activity during alkaline water electrolysis. Iron deposits variously have been reported to enhance nickel electrode activity by providing additional surface area from electrolytic deposition of solution phase iron species or to depassivate nickel electrodes via a surface interaction effect. In this study, nickel electrodes were sputtered with a smooth iron layer to determine the effect of metallic iron on the electrode surface without significantly changing the electrode surface area. A permeation cell with 8 mol/L KOH at 70 °C was used to follow nickel electrode potentials during hydrogen evolution while the permeation current was used to detect changes in the electrode structure.Short term measurements reveal no difference in behavior of coated and non-coated electrodes. Longer term results showed that a metallic iron coating on nickel electrodes prevented deactivation of the electrodes. The deactivation effect was associated with an increased hydrogen flux through the electrodes indicative of an elevated hydrogen concentration at the electrode surface. This high surface concentration is concluded to be the result of nickel hydride phase formation at the surface of the nickel electrodes. The iron coating prevents this surface phase from forming and hence prevents deactivation of the electrode.     

Techniques for Fabricating Nanoscale Catalytic Circuits

This paper describes the development of a new technique, atomic beam deposition (ABD), for the fabrication of catalysts with different active sites capable of catalyzing different chemical reactions. Using ABD, submonolayer amounts of Te and Cu atoms were deposited on vanadyl pyrophosphate (VPO) catalyst particles, and precise non-steady-state kinetic characterization was performed using the temporal analysis of products (TAP) reactor immediately following deposition. Results from TAP Knudsen pulse response experiments determine if small changes in the metal surface composition would produce detectable changes in catalytic properties. Partial oxidation of 1-butene to furan was used as the test reaction. Furthermore, this paper also demonstrates the sensitivity of the TAP reactor by measuring oxygen uptake on a single 350 μm diameter polycrystalline Pt particle packed in a bed with 100,000 inert quartz particles of similar dimensions. The Pt experiments demonstrate the precise manipulation of surface oxygen content.