The concentration of responsibility: An objective self-awareness analysis of group size effects in helping situations.

On the basis of the Gestalt figure-ground principle, an objective self-awareness theory interpretation of group size effects in helping situations was proposed. From this perspective, the diffusion of responsibility effect commonly observed in helping research is the decreasing likelihood of bystander objective self-awareness, and hence bystander intervention, that accompanies increases in the size of the bystander group. A complementary concentration of responsibility hypothesis derived from this analysis states that an increasing likelihood of bystander objective self-awareness, and therefore of bystander aiding behavior, is associated with increases in the size of the victim group. An experiment with 48 undergraduates tested this hypothesis in a 2–2 design varying number of potential helpers (1 vs 3) and number of victims (1 vs 3). Results show that straightforward appeals for help were more likely to be met with assistance when there were fewer potential helpers or more victims; thus, both the diffusion and concentration of responsibility were observed. Ratings of attentional focus obtained from 126 observer-Ss in a simulation of this experiment further substantiated the contention that these effects are attributable to variations in self-focused attention experienced by potential helpers. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Positive Gordon–Wixom coordinates

We introduce a new construction of transfinite barycentric coordinates for arbitrary closed sets in two dimensions. Our method extends weighted Gordon–Wixom interpolation to non-convex shapes and produces coordinates that are positive everywhere in the interior of the domain and that are smooth for shapes with smooth boundaries. We achieve these properties by using the distance to lines tangent to the boundary curve to define a weight function that is positive and smooth. We derive closed-form expressions for arbitrary polygons in two dimensions and compare the basis functions of our coordinates with several other types of barycentric coordinates.     

MiHOS: an approach to support handling the mismatches between system requirements and COTS products

In the process of selecting Commercial Off-The-Shelf (COTS) products, it is inevitable to encounter mismatches between system requirements and COTS products. These mismatches occur as a result of an excess or shortage of the COTS attributes. This paper proposes a decision support approach, called MiHOS (Mismatch Handling for COTS Selection), that aims at addressing COTS mismatches during and after the selection process. MiHOS can be integrated with existing COTS selection methods at two points: (1) For evaluating COTS candidates: MiHOS estimates the anticipated fitness of the candidates if their mismatches are resolved. This helps to base our COTS selection decisions on the fitness that the candidates will eventually have if selected. (2) Mismatch resolution after selecting a COTS product: MiHOS suggests alternative plans for resolving the most appropriate mismatches using suitable actions, such that the most important risk, technical, and resource constraints are met. A case-study is used to illustrate MiHOS and to discuss its added value.

New all solid‐state polymer electrolyte based on epoxy resin and ionic liquid for high temperature applications

Flexible epoxy network loaded with high amount of ionic liquid (IL) 1‐decyl‐3‐methylimidazolium bromide ([DMIM]Br) has been reported by using a mixture of polyol amine as curing agent. The IL presents good electrochemical response even at 170 °C, as no evidence of redox reactions was observed. The incorporation of as high as 50 wt % of this IL within the epoxy matrix resulted in solid and flexible electrolyte with good thermal stability below 180 °C, as measured by thermogravimetric analysis and ionic conductivity of around 10^?6 S cm^?1 at room temperature and higher than 10^?3 S cm^?1 at high temperature. This electrolyte presented a prodigious potential for applications in electrochemical devices at high temperature like batteries and supercapacitors, and the flexibility of this solid electrolyte persist at low temperature because of its low glass transition temperature. Furthermore, leakage problems were not observed. Thereby, impedance spectroscopy and cyclic voltammetry were performed to characterize the electrochemical properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45838.     

Salmonella Thompson associated with improper handling of roast beef at a restaurant in Sioux Falls, South Dakota

In October 1996, we investigated an outbreak of Salmonella serotype Thompson infections associated with Restaurant A in Sioux Falls, South Dakota, and conducted two cohort studies among persons who ate at luncheons catered by Restaurant A. Fifty-two Salmonella Thompson infections were identified between 29 September and 14 October 1996. Infections occurred among employees and patrons at Restaurant A and among attendees at three luncheons catered by the restaurant on 7 October. Roast beef cooked at Restaurant A was the only food item significantly associated with illness. Cooking times and storage temperatures for roast beef were inadequate to prevent multiplication of Salmonella, and the chefs were unaware of proper cooking and storage temperatures. We conclude that improper handling of roast beef probably caused this outbreak of Salmonella Thompson infections. Better knowledge of food safety practices by the cooking staff at Restaurant A, through required food safety education, might have prevented the outbreak.     

Lipidemic effects of an interesterified mixture of butter, medium-chain triacylglycerol and safflower oils

The objective of this study was to determine if the positional structure of dietary triacylglycerol affected lipidemic responses. Thirty healthy adults (16 men and 14 postmenopausal women) with low-density lipoprotein cholesterol (LDL-C) concentrations >3.37 mM (130 mg/dl) enrolled in a prospective, single-blind, cross-over outpatient clinical trial that consisted of two 5-wk dietary phases. After baseline screening, subjects were instructed to follow individualized meal plans (weight maintenance diets with 36% of total energy from fat, half of which was from a test oil) and randomized to receive either butter (B) or an interesterified mixture (IM) of butter, medium-chain triacylglycerol (MCI), and safflower oils. Blood drawn during weeks 5 and 10 of feeding was analyzed for total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), LDL-C, and triacylglycerols (TAG). Mean plasma levels of TC (B, 6.98±1.06 mM; IM, 7.09±1.20 mM), HDL-C (B,1.30±0.35 mM; IM, 1.29±0.34 mM), and LDL-C (B, 4.91±0.95 mM; IM, 492±1.10 mM) were not significantly different between the two dietary treatments. Mean TAG levels were higher for the interesterified B-MCT mixture (B, 1.75±0.72 mM; IM, 1.96±0.86 mM, P<0.05). We conclude that an IM of B, MCT and safflower oils as compared to native B has no appreciable effect on plasma cholesterol concentrations but is associated with a modest rise in plasma TAG.     

Reproducibility of electron microscope magnifications with digital display of individual lens currents

Quantitative measurements on electron micrographs with less than 10% error require precise calibration of all lenses contributing to the final image magnification. Calibration of the magnification to approximately 1.5% is easily attained by using simple statistical methods and a digital display milliampere meter capable of measuring the objective, intermediate and projector lens currents independently. The method detailed, readily adaptable to other electron microscopes, requires the projector lens current be held constant, with the magnification determined by varying the intermediate lens current and corrections made on the basis of calibrated objective lens current effect. The errors of magnification, approximately 1.5%, are the same range as the test grid variation which appears to be the limiting factor. Even with this limitation, magnifications have been determined reproducible to within less than 0.2% in daily use over a 6 month period.     

Polypropylene/poly(lactic acid)/carbon nanotube semi-biodegradable nanocomposites: The effect of sequential mixing approach and compatibilization on morphology,rheology and electrical conductivity

Semi-biodegradable polypropylene (PP)/poly(lactic acid) (PLA) (50:50 vol%) blend loaded with 0.6 vol% of pristine carbon nanotube (CNT) were prepared by melt compounding the components using different sequential mixing strategies: (i) all components together (PP/PLA/CNT); (ii) PP first mixed with CNT (PP@CNT/EVA) and (iii) EVA first mixed with CNT (EVA@CNT/PP). The composites presented co-continuous structure and the CNT selectively localized inside the PP phase or at the interface, regardless the order of the CNT addition into the mixing. These features were confirmed by selective extraction experiments and morphological studies: optical, scanning electron, and transmission electron microscopy. However, the preferential localization at the interface was predicted from wetting coefficient, determined from interfacial energy. Higher electrical conductivity values were achieved by using the one-step mixing approach, were all components were mixed together, whose value of around 10⁻⁴ S/m was achieved by adding 0.6 vol% of CNT to the blend. The compatibilization with polypropylene-g-maleic anhydride increased the melt viscosity of the blend and composite but did not affect the conductivity or the tensile properties of the CNT-based composite.     

Toughened epoxy-liquid polybutadiene networks cured with anhydride with outstanding thermal and mechanical properties

Toughened epoxy systems cured with anhydride-based hardener were successfully prepared by incorporating nonpolar liquid polybutadiene (PB) previously functionalized with isocyanate groups (PBNCO). The NCO groups in PBNCO react with the hydroxyl and/or epoxy groups of the matrix forming a ER-PB-ER triblock copolymer. The block copolymer is evidenced by transmission electron microscopy (TEM). In fact the modified epoxy resin (ER) networks presented domains with cocontinuous-like morphology, composed by PB and ER phases in nanomeric dimensions. The effect of PBNCO on the curing process of ER was studied by rheometry. Also the resulting networks were characterized by mechanical and dynamic mechanical properties, differential scanning calorimetry, and TEM. By adding an amount of rubber as high as 20 phr, a great improvement of toughness (around 140%) and impact resistance as well as a good transparency were achieved without significantly affecting the modulus and stiffness. Also the glass transition temperature (Tg) increased around 10°C with the presence of 5 phr of PBNCO. Even with the addition of 20 phr of rubber, the Tg of the system was superior than that found for the neat epoxy network. The outstanding physic-mechanical performance is attributed to the peculiar morphology.