Use of a 13C tracer to quantify the plasma appearance of a physiological dose of lutein in humans

Increased intake of lutein from vegetables promotes increased density of the macular pigment and therefore may protect against age-related macular degeneration. Our objective was to use a ¹³C tracer and high-precision gas chromatography-combustion interfaced-isotope ratio mass spectrometry (GC-C-IRMS) to investigate metabolism of a lutein dose equivalent to that absorbed from vegetables. Biosynthetic per-labeled (>99% ¹³C) lutein was purified from a commercially available extract of algal biomass. Subjects (n=4) ingested 3 mg of [¹³C]lutein with a standardized low-carotenoid breakfast. Blood samples were collected at baseline and then hourly for 12 h; additional blood samples were drawn at 16, 24, 48, 72, 96, 192, 360, and 528 h. To produce perhydro-β-carotene suitable for analysis by GC-C-IRMS, the plasma lutein fraction was hydrogenated on palladium-on-carbon catalyst with acid-catalyzed hydrogenolysis. The stable carbon isotope (¹³C/¹²C) ratio measured by GC-C-IRMS was used to calculate the plasma concentration of [¹³C]lutein. There was a rapid increase in [¹³C]lutein in plasma until peak enrichment at 16 h followed by a decline to the next measurement at 24 h. At 528 h, small changes in ¹³C enrichment from baseline could still be measured in plasma lutein. High-precision GC-C-IRMS enables complete definition of the appearance and disappearance of [¹³C]lutein in plasma after ingestion of a dose similar to that absorbed from foods.     

Evaluative pressure in mothers: Effects of situation, maternal, and child characteristics on autonomy supportive versus controlling behavior.

This study examined the effects of situational pressure and maternal characteristics (social contingent self-worth, controlling parenting attitudes) on mothers' autonomy support versus control in the social domain. Sixty 4th-grade children and their mothers worked on a laboratory task in preparation for meeting new children, with mothers in either an evaluation (mothers told their child would be evaluated by other children) or no-evaluation (no mention of evaluation) condition. Mothers in the evaluation condition spent more time giving answers to their children. Mothers with controlling parenting attitudes exhibited more controlling behavior. Further, mothers with high social contingent self-worth in the evaluation condition were most controlling. Results suggest the importance of interactions between situations and maternal characteristics in determining levels of mothers' autonomy support versus control and have implications for helping parents support children's autonomy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimizing XML queries: Bitmapped materialized views vs. indexes

Optimizing queries using materialized views has not been addressed adequately in the context of XML due to the many limitations associated with the definition and usability of materialized views in traditional XML query evaluation models.     

From majority to minority and vice versa: The asymmetrical effects of losing and gaining majority position within a group.

Two studies examined the effects of stable, partially changed, and completely changed majority and minority positions within a group on perception and evaluation of the group. It was hypothesized that loss of majority position (majority-to-minority change) would have stronger effects than gain of majority position (minority-to-majority change). The hypothesized asymmetrical effect was demonstrated in that loss of majority position decreased perception of group—self similarity, group attraction, and expectations for positive interactions with the group, whereas a corresponding gain of position did not increase them. Thus immediately following changes, the group is especially fragile because disintegrative forces created by the loss of majority position are stronger than integrative forces created by the gain of majority position. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of platinum salt concentration on the electrospinning of polyacrylonitrile/platinum acetylacetonate solution

The preparation and characterization of electrospun polyacrylonitrile (PAN)/platinum(II) acetylacetonate composite nanofibers were investigated. The solution properties, such as viscosity, surface tension, and conductivity, of Pt‐acetylacetonate‐added PAN solutions in N,N‐dimethylformamide were measured, and their influences on the resulting fiber structure were also determined. At low Pt salt concentrations, the addition of Pt salt increased the fiber diameter but did not change the fiber diameter distribution. However, the fiber diameter decreased, and the fiber diameter distribution became broader when the Pt salt concentration went beyond a critical value. The structure of the electrospun fibers was determined by the formation of polymer–salt– solvent interactions, which changed the balance among the viscosity, surface tension, and conductivity of the solutions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

An empirical examination of self-reported work stress among U.S. managers.

This study proposes that self-reported work stress among U.S. managers is differentially related (positively and negatively) to work outcomes depending on the stressors that are being evaluated. Specific hypotheses were derived from this general proposition and tested using a sample of 1,886 U.S. managers and longitudinal data. Regression results indicate that challenge-related self-reported stress is positively related to job satisfaction and negatively related to job search. In contrast, hindrance-related self-reported stress is negatively related to job satisfaction and positively related to job search and turnover. Future research directions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perspectives on intelligence testing, affirmative action, and educational policy.

The often-vitriolic debate on intelligence testing, affirmative action, and educational policy encompasses issues of deep social, political, economical, and emotional significance to all Americans. This special theme issue focuses on the current thinking of leading scholars in the areas of intelligence testing, affirmative action, and educational policy. This introduction to the theme issue begins with an overview of key data and observations that place the debate into sharper focus. Next, the major areas of scholarly work relevant to the debate are reviewed. Finally, the contributors and their major points of view are introduced to orient the reader for the journey through the 21 articles and commentary that comprise this volume. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The HMG-CoA Reductase Gene and Lipid and Lipoprotein Levels: the Multi-Ethnic Study of Atherosclerosis

HMG-CoA reductase (HMGCR) is an enzyme involved in cholesterol synthesis. To investigate the contribution of the HMGCR gene to lipids and lipoprotein subfractions in different ethnicities, we performed an association study in the Multi-Ethnic Study of Atherosclerosis (MESA). In total, 2,444 MESA subjects [597 African-Americans (AA), 627 Chinese-Americans (CHA), 612 European-Americans (EA), and 608 Hispanic-Americans (HA)] without statin use were included. Participants had measurements of blood pressure, anthropometry, and fasting blood samples. Subjects were genotyped for 10 single nucleotide polymorphisms (SNPs). After excluding SNPs with minor allele frequency <5%, a single block was constructed. The most frequent haplotype was H1 (41–56%) in all ethnic groups except AA (H2a, 44.9%). Lower triglyceride level was associated with the H2a haplotype in AA and H2 in HA. In HA, H4 carriers had higher levels of triglyceride and small low-density lipoprotein (s-LDL), and lower high-density lipoprotein cholesterol (HDL-c), while carriers with H7 or H8 had associations with these traits in the opposite direction. No significant association was discovered in both CHA and EA. The total variation for triglyceride that could be explained by H2 alone was 2.6% in HA and 1.4% in AA. In conclusion, HMGCR gene variation is associated with multiple lipid/lipoprotein traits, especially with triglyceride, s-LDL, and HDL-c. The impact of the genetic variance is modest and differs greatly among ethnicities.     

Managing discrimination in selection: The influence of directives from an authority and social dominance orientation.

The authors examined one manner in which to decrease the negative impact of social dominance orientation (SDO), an individual difference variable that indicates support for the "domination of 'inferior' groups by 'superior' groups" (J. Sidanius & F. Pratto, 1999, p. 48), on the selection of candidates from low-status groups within society. Consistent with the tenets of social dominance theory, in 2 studies we found that those high in SDO reported that they were less likely to select a potential team member who is a member of a low-status group (i.e., a White female in Study 1 and a Black male in Study 2) than those low in SDO. However, explicit directives from an authority moderated this effect such that those high in SDO were more likely to select both candidates when authority figures clearly communicated that job performance indicators should be used when choosing team members. Thus, our studies suggest that the negative effects of SDO may be attenuated if those high in SDO are instructed by superiors to use legitimate performance criteria to evaluate job candidates. (PsycINFO Database Record (c) 2010 APA, all rights reserved)