The influence of a friend's perspective on American Indian children's recall of previously misconstrued events.

The ability of American Indian children (N = 99; 7–12 years of age) to reframe a memory of a friend's seemingly mean-spirited actions (Story 1) after hearing the friend's perspective detailing her/his good intentions (Story 2) was explored. Children in a control group heard an unrelated Story 2 and did not alter their retelling of Story 1. Good verbal skills facilitated the integration of the friend's perspective in memory for the children who heard the friend's explanation. Higher scores on the working memory and inhibition tasks were associated with higher verbal ability scores. Older children had better working memory and inhibitory skills than younger children. Cultural engagement predicted better social competence ratings but not higher memory reframing scores as predicted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acrylamide content in potato chips on the Italian market determined by liquid chromatography tandem mass spectrometry

An easy‐to‐use and simplified liquid chromatography‐tandem mass spectrometry (LC‐ESI (+)‐MS/MS) method was adopted to determine the amount of acrylamide in thirty‐two samples of potato chips purchased on the South Italian market in 2009. Extract produced from matrices was directly analysed without derivatisation, the use of isotopically labelled acrylamide or the use of clean up cartridges. Quality analytical data were reported. The limit of detection and limit of quantification were 6 μg kg^?1 and 18 μg kg^?1, respectively and recovery values ranged from 90.7–96.3%. The relative standard deviation (RSD) ranged between 2.1% and 5.8%. The values ranged between 27 and 1400 μg kg^?1 and the arithmetic mean acrylamide content resulted 363 μg kg^?1. According to Foot et al. [Food Additives and Contaminants, 24 (2007)(S1), 37] and considering 500 μg kg^?1 as the minimum level possible with the actual available mitigation tools, the number of samples showing an acrylamide level higher than 500 μg kg^?1 resulted to be 22%. This paper gives a contribution to data collection in response to the monitoring activity of EFSA and following the Commission Recommendation 2007/331/EC: really, the number of Italian samples of potato chips and potato products for which acrylamide values was reported in the ‘results on the monitoring of acrylamide’ of EFSA ( http://www.efsa.europa.eu/cs/BlobServer/Report/datex_report_acrylamide_en,0.pdf?ssbinary=true , 2009) issued on 30 April 2009 is very limited.     

Effect of process unit operations and long-term storage on catechin contents in EGCG-enriched tea drink

Due to the increasing market for functional foods and the chemopreventive action of (?)-epigallocatechin gallate (EGCG), manufacturers produce ready-to-drink green tea infusions enriched or not in EGCG. However, the maintenance of green tea catechins stability in drinks is always a challenge. In this context, the objectives of this study were (1) to assess the catechin stability in tea drink during a 6-month storage, (2) to evaluate the impact of process unit operations on catechin stability and (3) to compare the catechin and caffeine contents of commercially available tea drinks. It appeared that the stability of catechins during long-term storage was optimum at low temperature (4 °C) and acidic pH (pH 4.0). During the processing of the EGCG-enriched green tea drink, all the process unit operations, except heat-treatment, had no impact on catechin concentrations. In addition, in commercially available tea drinks, except enriched green tea drinks, their catechin contents are very low to provide health benefits.     

And Yet it Moves! Microfluidics Without Channels and Troughs

A simple, versatile, rapid, and inexpensive procedure based on the immersion method is developed to fabricate chemical gradients on chemically activated Si/SiO₂ surfaces by a trichloro (1H,1H,2H,2H‐perfluorooctyl) silane self‐assembly monolayer (SAM). Contact angle measurements, atomic force microscopy, and X‐ray photoelectron spectroscopy data based on the intensity of the signals of C1s and F1s, which progressively increase, indicate that the surface is characterized by the presence of increasing amounts of the SAM along the gradient direction. Experimental conditions are optimized by maximizing the variation of the contact angle of water drops at the starting and the ending points of the gradient. The application of the chemical gradient to droplet motion is demonstrated. The results are rationalized by dissipative particle dynamics simulations that well match the observed contact angles and the velocities of the drops. The simulations also show that the intrinsic nature of the gradient affects the velocity of the motion.     

A Controlled-Potential and Derivative DC Polarograph for Regular and First and Second Derivative DC Polarography: Circuits,Theory, and Performance Characteristics. Advantages of Rapid and Derivative DC Polarography†

SUMMARY

The circuits, theory, and performance characteristics are described of a controlled-potential dc polarograph (ORNL Model Q-1988-FES) which is designed to take advantage of the inherent high sensitivity and resolution of derivative dc polarography. Several circuit modifications for specific applications are described. Cell and electrode design considerations are given. The advantages of potentiostatic electrolysis in polarography, the advantages of the use of current-averaging and analog derivative circuits in improving the measurement and the interpretation of recorded dc polarograms, the attainment of ultimate high resolution through the recording of first derivative dc polarograms of good waveform, the achievement of high sensitivity by means of rapid derivative dc polarography, the practical advantages of first derivative over regular dc polarography, the relative advantages of first and second derivative dc polarography, and the practical advantages of rapid dc polarography are discussed. Conclusions are illustrated and substantiated by data.     

In situ characterization of metal hydride thermal transport properties

Thermal property characterization of a metal hydride was conducted in a high pressure hydrogen environment with a transient plane source apparatus. This apparatus was integrated with a pressure vessel to measure the effective thermal conductivity and the thermal diffusivity of non-reactive and activated metal hydrides in hydrogen pressures up to 275 bar and 253 bar, respectively. In a non-reactive oxidized condition, the effective thermal conductivity of Ti_1.1CrMn powder increased with hydrogen pressure from 0.8 to 1.6 W/m·K. For activated powder, effective thermal conductivity increased from 0.3 to 0.7 W/m·K with hydrogen pressure. It is postulated that the smaller particle size associated with the reactive condition caused the reduction in effective thermal conductivity. Also, the derived specific heat of the activated Ti_1.1CrMn increased with reaction progress by a factor of two, with a maximum value at the fully hydrided state.     

Effects of pressure-shift freezing and conventional freezing on model food gels

Summary Gels of agar, starch, ovalbumin, gelatin and an industrial β-lactoglobulin protein isolate, were frozen conventionally in a −30 °C freezer and by pressure-shift freezing at 200 MPa at −15 °C. Thawing was carried out conventionally at 20 °C and by the application of a pressure of 200 MPa. The microscopic structure and mechanical properties of the thawed gels were compared with those of the initial gels. Microscopic examination showed that pressure-shift freezing produces smaller and more uniform ice crystal damage than conventional freezing at −30 °C. The results also suggest that the freeze-thaw behaviour of food gels can be categorized into two general types: (1) gels which have a reduced gel strength as a result of mechanical damage to the gel microstructure caused by ice crystal formation, and (2) gels which have an enhanced gel strength, as a result of molecular structural changes that take place in the frozen state. Agar and gelatin were found to be typical of type (1) gels, whereas starch, β-lactoglobulin protein isolate and ovalbumin were found to be typical of type (2) gels. In the case of starch, retrogradation during thawing was found to be the most important factor.