Age-related variation in the influences of aging stereotypes on memory in adulthood.

Adults 24-86 years of age read positive or negative information about aging and memory prior to a memory test. The impact of this information on recall performance varied with age. Performance in the youngest and oldest participants was minimally affected by stereotype activation. Adults in their 60s exhibited weak effects consistent with the operation of stereotype threat, whereas middle-age adults exhibited a contrast effect in memory performance, suggestive of stereotype lift. Beliefs about aging and memory were also affected by stereotypic information, and older adults' changed beliefs were more important in predicting performance than was exposure to stereotype-based information alone. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The early childhood enterprise: Care and education of the young.

Reviews the historical development of early education and childcare in the US and suggests that young children and their families have many unmet needs. Psychology's contributions to the development of early education programs and its role in understanding the influence of these programs on later intellectual and social development are described. It is posited that the changing roles of women and the changing structure of family life have fostered new attitudes toward childcare. Given the fact that single-parent and dual-career families are the majority family forms in the 1980's, it is argued that there needs to be improved coordination among professionals concerned with childcare and education and that there is a need to develop a national policy for young children. (44 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of task strain, social conflict, and emotional activation on ambulatory cardiovascular activity: Daily life consequences of recurring stress in a multiethnic adult sample.

Ambulatory blood pressure (ABP) may be an independent predictor of cardiovascular endpoints, but little is known about its psychosocial determinants. The acute effects of psychosocial processes on cardiovascular activity during daily life were examined by random-effects regression. Healthy adults (N?=?120) were monitored over a 6-day period with ABP monitors and computer-assisted self-report assessments. Task strain, social conflict, and emotional activation were rated following each ABP measurement, as were activity, posture, and other covariates. Results show that blood pressure) (BP) and heart rate (HR) were elevated during periods of emotional activation (high negative affect or high arousal). Diastolic BP was lower during periods involving high decisional control, and HR was lower during high-control, low-demand activities. There were substantial individual differences in the effects of psychosocial influences on ambulatory cardiovascular activity. Psychological factors are reliable determinants of ABP, which may account for the unique predictive value of ABP. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of fill factor and validation of characterizing the degree of mixing in polymer nanocomposites

Polymer nanocomposites have been studied extensively, but few references mention the importance of processing and how to characterize the degree of mixing. In this work, we report the influence of fill factor on the degree of mixing and thermal properties for a nanocomposite system consisting of alumina nanoparticles in polyethylene terephthalate (PET) prepared in a batch mixer. The degree of mixing for the resultant polymeric nanocomposites was quantified by three different techniques; TEM particle density, Morisita's index, and skewness. All of these methods quantify the degree of mixing based on the number of the particles in selected areas of TEM images using image analysis software. TEM particle density and skewness gave similar results, with a maximum in the degree of mixing around a fill factor of 0.70, while Morisita's index displayed a constant increase in degree of mixing with increasing fill factor. T_g was depressed by the filler and with increasing degree of mixing. The depression of T_g in the composite was maximized at a fill factor of 0.70, confirming that the analysis of TEM particle density and skewness are valid techniques to assess the degree of mixing. POLYM. ENG. SCI., 47:2049–2056, 2007. © 2007 Society of Plastics Engineers     

RpoN Regulates Virulence Factors of Pseudomonas aeruginosa via Modulating the PqsR Quorum Sensing Regulator

The alternative sigma factor RpoN regulates many cell functions, such as motility, quorum sensing, and virulence in the opportunistic pathogen Pseudomonas aeruginosa (P. aeruginosa). P. aeruginosa often evolves rpoN-negative variants during the chronic infection in cystic fibrosis patients. It is unclear how RpoN interacts with other regulatory mechanisms to control virulence of P. aeruginosa. In this study, we show that RpoN modulates the function of PqsR, a quorum sensing receptor regulating production of virulence factors including the phenazine pyocyanin. The ∆rpoN mutant is able to synthesize 4-quinolone signal molecule HHQ but unable to activate PqsR and Pseudomonas quinolone signal (pqs) quorum sensing. The ∆rpoN mutant produces minimal level of pyocyanin and is unable to produce the anti-staphylococcal agents. Providing pqsR in trans in the ∆rpoN mutant restores its pqs quorum sensing and virulence factor production to the wild-type level. Our study provides evidence that RpoN has a regulatory effect on P. aeruginosa virulence through modulating the function of the PqsR quorum sensing regulator.     

Structural dependence of crystallization in glasses along the nepheline (NaAlSiO4) ‐ eucryptite (LiAlSiO4) join

Lithium and sodium aluminosilicates are important glass‐forming systems for commercial glass‐ceramics, as well as being important model systems for ion transport in battery studies. In addition, uncontrolled crystallization of LiAlSiO₄ (eucryptite) in high‐Li₂O compositions, analogous to the more well‐known problem of NaAlSiO₄ (nepheline) crystallization, can cause concerns for long‐term chemical durability in nuclear waste glasses. To study the relationships between glass structure and crystallization, nine glasses were synthesized in the Li_xNa_1‐xAlSiO₄ series, from x = 0 to x = 1. Raman spectra, nuclear magnetic resonance (NMR) spectroscopy (Li‐7, Na‐23, Al‐27, Si‐29), and X‐ray diffraction were used to study the quenched and heat‐treated glasses. It was found that different LiAlSiO₄ and NaAlSiO₄ crystal phases crystallize from the glass depending on the Li/Na ratio. Raman and NMR spectra of quenched glasses suggest similar structures regardless of alkali substitution. Li‐7 and Na‐23 NMR spectra of the glass‐ceramics near the endmember compositions show evidence of several differentiable sites distinct from known Li_xNa_1‐xAlSiO₄ crystalline phases, suggesting that these measurements can reveal subtle chemical environment differences in mixed‐alkali systems, similar to what has been observed for zeolites.     

The Clouding of an Anionic Surfactant in Acid Solution: Mechanistic and Analytical Implications

The clouding of sodium dodecyl sulfate (SDS) in strongly acidic solutions has seen analytical use, but its mechanism has generally been misinterpreted. In the present work it was found that as SDS slowly hydrolyzes to form dodecanol, the solution passes through a series of compositions at which the aggregation of surfactant is promoted by nucleation onto traces of insoluble dodecanol. This occurred at concentrations well below the critical micelle concentration of SDS and resulted in mixed aggregates that grew to macroscopic size, giving the solution a cloudy appearance. The increasing dodecanol content eventually caused coalescence into a coacervate phase which evolved into a solid layer of dehydrated dodecanol. The process, which continued over an extended period, depended on the temperature and the concentration and type of acid used. The early stages of SDS aggregation were monitored through the I ₁/I ₃ ratio of pyrene fluorescence, which confirmed the existence of micelle-like aggregates at low surfactant concentration. The mixed SDS/dodecanol systems formed in acid hydrolysis were mimicked in neutral solution by combining the appropriate amounts of SDS, dodecanol, and NaCl. Clouding and the formation of a coacervate phase generally proceeded in a similar manner in these solutions.     

Investigating the effects of IS strategic leadership on organizational benefits from the perspective of CIO strategic roles

In this study, the effects of IS strategic leadership on organizational outcomes are examined from the perspective of CIO strategic roles. A field survey is conducted that collects data from 110 matched pairs of CIOs and business executives within organizations. Our findings suggest that strategic leadership significantly affects both organizational benefits and information system quality. Further, we found that IS quality significantly mediates the relationship between IS strategic leadership and organizational benefits. We also note that IS vision significantly moderates the relationship between IS strategic leadership and IS quality, although it does not moderate the relationship between IS strategic leadership and organizational benefits or the relationship between IS quality and organizational benefits.     

Seasonal Frost Effects on the Soil–Foundation–Structure Interaction System

This paper presents the results of more than one year’s monitoring efforts and analysis of the effects of environmental variables on the dynamic properties of a selected bridge in Anchorage, Alaska. A seismic monitoring system was installed on the bridge to study these effects. The dynamic properties of the bridge have been identified from the recorded time histories which include ambient noises, traffic-induced vibrations, and small-magnitude earthquakes. Hourly air temperature data from nearby meteorological station during the period of study were collected to estimate the frozen soil depth for modeling purpose. A finite-element model and multiple-input autoregressive model were applied to study the effects of environmental variables on the dynamic properties. The results show that the environmental variables can significantly affect the dynamic properties by modifying the stiffness of the bridge system and the seasonal frost is found to have the dominating effects over air temperature on the bridge dynamic properties in cold regions. The results show that the models explain well the variation of dynamic properties with environmental variables.