Category Norms as a Function of Culture and Age: Comparisons of Item Responses to 105 Categories by American and Chinese Adults.

Understanding how aging influences cognition across different cultures has been hindered by a lack of standardized, cross-referenced verbal stimuli. This study introduces a database of such item-level stimuli for both younger and older adults, in China and the United States, and makes 3 distinct contributions. First, the authors specify which item categories generalize across age and/or cultural groups, rigorously quantifying differences among them. Second, they introduce novel, powerful methods to measure between-group differences in freely generated ranked data, the rank-ordered logit model and Hellinger Affinity. Finally, a broad archive of tested, cross-linguistic stimuli is now freely available to researchers: data, similarity measures, and all stimulus materials for 105 categories and 4 culture-by-age groups, comprising over 10,000 fully translated unique item responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Micromechanical modelling of ductile crack growth in the binder phase of WC–Co

This study focuses on numerical simulation of ductile failure in the Co binder phase of WC–Co hardmetal. The growth of edge cracks under mode I loading is considered. A computational micromechanics approach is taken where the Co binder ligaments are explicitly represented in finite element models. An embedding technique is employed. Crystal plasticity theory is used to represent plastic deformation in the Co ligaments. Crack propagation in the binder is simulated using an element removal technique based on a modified Rice and Tracey model for ductile void growth, and fracture resistance curves are generated. Parameter studies are performed for variations in microstructrual parameters such as numbers of Co ligaments ahead of the crack tip and local Co volume fraction. The importance of thermal residual stresses and finite element mesh density are also investigated.     

Comprehension of arithmetic word problems: A comparison of successful and unsuccessful problem solvers.

It is proposed that when solving an arithmetic word problem, unsuccessful problem solvers base their solution plan on numbers and keywords that they select from the problem (the direct translation strategy), whereas successful problem solvers construct a model of the situation described in the problem and base their solution plan on this model (the problem-model strategy). Evidence for this hypothesis was obtained in 2 experiments. In Experiment 1, the eye fixations of successful and unsuccessful problem solvers on words and numbers in the problem statement were compared. In Experiment 2, the degree to which successful and unsuccessful problem solvers remember the meaning and exact wording of word problems was examined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High-performance liquid chromatography of human milk triacylglycerols and gas chromatography of component fatty acids

Human milk triacylglycerols were separated by high-performance liquid chromatography. A 5-μ Supelcosil LC-18 column (Supelco, Inc., Bellefonte, PA) was used with acetone/acetonitrile (64∶36, vol/vol) as mobile phase. Triacylglycerols were tentatively identified based on theoretical carbon number and relative retention time. Despite changes resulting from dietary fat variation, the major component triacylglycerols were those composed of palmitic, oleic and linoleic acids. Triacylglycerols with palmitic, stearic and oleic acids were present as minor components. Fatty acids were quantified by gas chromatography relative to an internal standard. Ratios of n−6/n−3 fatty acids were found to be high than previously reported. Based on a paper presented at the Symposium on Milk Lipids held at the AOCS Annual Meeting, Baltimore, MD, April 1990.     

The influence of psychosocial factors on heart transplantation decisions and outcomes

In January 1990, a well-established heart transplant program added a psychosocial evaluation procedure to its medical evaluation of potential transplant recipients. To determine the predictive value of psychosocial evaluation for decisions to list patients for a transplant and for ultimate clinical outcomes, we reviewed records of 191 patients who underwent psychosocial evaluation in the subsequent 3 years. Informal prescreening for obvious psychopathology and other disqualifiers almost certainly restricted the ranges of psychosocial factors observed in the sample. Of 120 patients listed, 61 actually received transplants. Psychosocial factors were little used in deciding whether to list the patients and were not predictive of recipients' medical outcome or compliance, but were moderately predictive of complication rates and difficulty of managing patients after transplantation. Although psychosocial evaluation of prescreened potential transplant recipients has little value in predicting medical outcome, it may be useful for planning and scheduling care after transplantation.     

Memory scanning: Are fixed and varied sets scanned concurrently or successively?

Subjects were timed as they decided whether individually presented probe letters were or were not contained in pairs of memorized sets of one, two, or four letters. One set was fixed in advance of a block of trials, while the other varied from trial to trial. In Experiments 1 and 2, subjects responded positively if the probe was in either set and negatively otherwise; in Experiment 3 they made different responses to fixed-set, varied-set, and negative probes. In all three experiments, reaction time (RT) to varied-set probes depended more on the size of the varied set than of the fixed set, whereas RT to fixed-set and negative probes depended more on the size of the fixed set. These results were generally consistent with the hypothesis that scanning of the two sets was at least to some extent concurrent rather than successive, with the fixed set scanned more slowly than the varied set. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A specific,sensitive and high-capacity immunoassay for PAF

A specific radioimmunoassay for platelet-activating factor (PAF) sensitive in the range 10–1000 pg (0.02–2 pmoles) has been developed. Detailed quantitative hapten inhibition studies showed specificity for the acetyl group at C-2 of PAF, a requirement for the ether linkage at C-1 and some tolerance for substituents on the choline nitrogen. No significant cross-reactivity was found with phosphatidylcholine and lysophosphatidylcholine or with lysoPAF. Based on a paper presented at the Third International Conference on Platelet-Activating Factor and Structurally Related Alkyl Ether Lipids, Tokyo, Japan, May 1989.     

The distribution of brominated long-chain fatty acids in sponge and symbiont cell types from the tropical marine spongeAmphimedon terpenensis

The tropical marine spongeAmphimedon terpenensis (family Niphatidae, order Haplosclerida) has previously been shown to possess unusual lipids, including unusual fatty acids. The biosynthetic origin of these fatty acids is of interest as the sponge supports a significant population of eubacterial and cyanobacterial symbionts. The total fatty acid composition of the sponge was analyzed by gas chromatography/mass spectrometry of the methyl esters. Among the most abundant of the fatty acids in intact tissue were 16∶0, 18∶0 and 3,7,11,15-tetramethylhexadecanoic (phytanic) acid. In addition, three brominated fatty acids, (5E,9Z)-6-bromo-5,9-tetracosadienoic acid (24∶2Br), (5E,9Z)-6-bromo-5,9-pentacosadienoic acid (25∶2Br) and (5E,9Z)-6-bromo-5,9-hexacosadienoic acid (26∶2Br) were also present. The three brominated fatty acids, together with phytanic acid, were isolated from both ectosomoal (superficial) and choanosomal (internal) regions of the sponge. Analysis of extracts prepared from sponge/symbiont cells, partitioned by density gradient centrifugation on Ficoll, indicated that phytanic acid and the three brominated fatty acids were associated with sponge cells only. Further, a fatty acid methyl ester sample from intact tissue ofA. terpenensis was partitioned according to phospholipid class, and the brominated fatty acids were shown to be associated with the phosphatidylserine and phosphatidylethanolamine fractions that are commonly present in marine sponge lipids. The phosphatidylcholine and phosphatidylglycerol fractions were rich in the relatively shorter chain fatty acids (16∶0 and 18∶0). The association of brominated long-chain fatty acids (LCFA) with sponge cells has been confirmed. The findings allow comment on the use of fatty acid profiles in chemotaxonomy and permit further interpretation of LCFA biosynthetic pathways in sponges. The assignment of the sponge studied, which is currently placed asA. terpenensis, is being supported to some extent, but the species is unusual in having C₂₅ fatty acids as the major constituent in this group. Other factors, such as season or microenvironmental conditions, may influence observed fatty acid composition which tends to reduce the usefulness of fatty acid profiles as markers in sponge chemotaxonomy.     

Preliminary Assessment of Contaminants in Soft Sediments of the Detroit River

Soft sediments from the Detroit River were analyzed for the USEPA priority pollutants to generally characterize contaminant distribution. Forty-three were detected. Highest heavy metal concentrations were found in the Trenton Channel and immediately downstream of Grosse Ile. They ranged from an area mean (N = 2) of 0.19 mg/kg mercury to 338.7 mg/kg zinc (dry weight). Polynuclear aromatic hydrocarbons ranged from 0.1 mg/kg to 38.8 mg/kg (mean, N = 2) with the highest levels near Grosse Ile. PCBs ranged from 0.015 mg/kg to 1.7 mg/kg (mean, N = 2). Organochlorine pesticides were not detected except for a trace of heptachlor in one sample. Sediment contamination in the Detroit River is widespread with higher concentrations on the U.S. side downstream of the Rouge River and in the Trenton Channel. The significance of these in-place pollutants to biota and as a source to Lake Erie is still unknown.     

The study of sexual behavior in relation to the transmission of human immunodeficiency virus: Caveats and recommendations.

To create the behavior-change programs essential for limiting the acquired immune deficiency syndrome (AIDS) epidemic, we must obtain a precise understanding of the sexual behavior, knowledge, and attitudes of our nation's various ethnic, racial, social, age, regional, and sexual orientation groups. Such information is necessary for developing the precisely targeted educational programs that currently are our most effective means of reducing risk behaviors and halting the spread of the disease in the United States. These behavioral data are also crucial to biomedical investigations, making possible the identification of appropriate subjects for programs ranging from the testing of vaccines to the evaluation of the threat to pregnant women and their offspring. In this article, we summarize data on sexual behaviors associated with the transmission of the AIDS virus (i.e., human immunodeficiency virus [HIV]) and discuss selected issues relevant to the conduct of research on human sexuality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)