Induced Chiral Chromonics Confined in Micrometric Droplets

Chirality emergence in biological systems is common but the chiral expression from the molecular to macroscopic level in water-based systems is poorly understood. Among water-based systems, chromonic liquid crystals have recently received a lot of attention due to the spontaneous chirality they show when confined in curved geometries. Confinement of chiral-induced chromonics is not trivial since they are three component systems whose time stability is a delicate thermodynamic balance. In this work, a well-defined periodic Frank–Pryce texture, typical of chiral thermotropic liquid crystals, is observed in microspheres of a chiral induced chromonic embedded in a poly(dimethylsiloxane) matrix. This texture slowly degrades in time and a possible mechanism behind the degradation process is suggested via X-ray diffraction and atomic force microscopy measurements on thin chromonic films. To stabilize this texture and to control the structure periodicity, cations are added to the three components system in an attempt to tune the non-covalent interactions between molecules and supramolecular stacks. The study of the effects of this addition allows for better insight into the molecular interactions that occur in the chiral induced mesophase. This is a crucial point in view of possible biocompatible technological applications.     

Iron Transport across Symbiotic Membranes of Nitrogen-Fixing Legumes

Iron is an essential nutrient for the legume-rhizobia symbiosis and nitrogen-fixing bacteroids within root nodules of legumes have a very high demand for the metal. Within the infected cells of nodules, the bacteroids are surrounded by a plant membrane to form an organelle-like structure called the symbiosome. In this review, we focus on how iron is transported across the symbiosome membrane and accessed by the bacteroids.     

Professional psychology internships.

Questionnaire data from 167 directors of psychology internship training programs were analyzed. From the results, suggestions are offered for assisting internship applicants, improving training programs, and conducting research on internships. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of client/computer interaction on career decision-making processes.

Examined the impact of the System of Interactive Guidance Information (SIGI), a relatively new computer-assisted instructional system (CAI), on career decision-making processes of 72 volunteer undergraduates. The experimental treatment included pre–post testing, brief interviewing (15 min), and a 3-hr interaction, with SIGI scheduled in 1-hr time blocks within a 10-day period. Decision-making stage, as measured by the Vocational Decision-Making Checklist, and locus of control of reinforcement, as measured by Rotter's Internal–External Locus of Control Scale, were the outcome variables investigated. 48 undergraduates were randomly assigned to a treatment group and 24 to a wait/control group. Results show significant positive changes for the treatment group on pre–post measures of decision-making stage related to choice of college major. No significant changes were found on pre–post decision-making stage measures related to vocation or to locus of control of reinforcement. Results suggest that brief exposure to a CAI mode can have positive effects, particularly for improving skills related to choice of college major. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Knowledge of storybooks as a predictor of young children's vocabulary.

Shared book reading provides a rich source of linguistic stimulation for young children. The authors examined whether variations in knowledge of storybooks (assumed to index factors such as frequency of shared reading) were related to vocabulary scores for 3–6 yr olds. In Exp 1, parents' knowledge of storybooks explained unique variance in children's receptive vocabulary scores after controlling for children's analytic intelligence, parents' exposure to adult reading material, and parents' education. In Exp 2, children's knowledge of storybooks explained unique variance in their receptive and expressive vocabulary scores after controlling for parents' exposure to print and socioeconomic status level. Children's knowledge of storybooks indexed cognitive factors as well as exposure. The findings obtained in the 2 experiments suggest that storybook experiences during the preschool years may be an important influence on the development of children's language skills. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Smoking cessation and severity of disease: The Coronary Artery Smoking Intervention Study.

Tested the effectiveness of an individually delivered behavioral multicomponent smoking intervention (SI) against offering advice only (AO) to 267 patients (aged 30–75 yrs) after coronary arteriography. After 6 mo, 51% of AO Ss and 62% of SI Ss reported abstinence. Validated rates were 34% and 45% for AO and SI Ss, respectively. At 6 mo, the SI had the most effect for Ss with more severe coronary artery disease (CAD) who had been admitted with a myocardial infarction even after controlling for baseline characteristics such as stage of readiness for change, sex, and self-efficacy. At 12 mo follow-up, only severity of disease mediated SI effects. Similar results were seen for cotinine-validated cessation. Data confirm the effectiveness of individually administered SI for more seriously ill patients with CAD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Iodine Deficiency and the Brain: Effects and Mechanisms

Iodine is an essential micronutrient needed in human diets. As iodine is an integral component of thyroid hormone, it mediates the effects of thyroid hormone on brain development. Iodine deficiency is the most prevalent and preventable cause of mental impairment in the world. The exact mechanism through which iodine influences the brain is unclear, but is generally thought to begin with genetic expression. Many brain structures and systems appear to be affected with iodine deficiency, including areas such as the hippocampus, microstructures such as myelin, and neurotransmitters. The clearest evidence comes from the studies examining cognition in the cases of iodine deprivation or interventions involving iodine supplementation. Nevertheless, there are many inconsistencies and gaps in the literature of iodine deficiency, especially over the lifespan. This paper summarizes the literature on this topic, suggests a causal mechanism for iodine's effect on the brain, and indicates areas for the future research (e.g., using magnetic resonance imaging (MRI) and functional MRI to examine how iodine supplementation facilitates cognitive functioning).     

Chiral luminescent compounds as a perspective for cholesteric liquid crystal lasers

We present the synthesis and characterization of fluorene based materials for mirror less laser applications. Mirror less lasing is obtained from a cholesteric liquid crystals mixture, that acts as a resonator, doped with a photoluminescent dye, that acts as an active medium. We propose to use fluorene based compounds to combine two necessary properties to achieve laser emission: chirality and luminescence. Two different compounds, a trimer and an oligomer are synthesized. The trimer and the oligomer are both prepared with chiral moieties and, in addition, they are liquid crystalline compatible. More, oligofluorenes are good blue emitters and the emission quantum yield is around 0.8 in the violet–blue range. These fluorene based compounds are used in cholesteric liquid crystals mixtures as luminescent chiral dopants and a fine tuning of the laser emission is obtained. The dependence of lasing efficiency on concentration and the handedness of chiral luminescent dopants are investigated.     

For better and for worse: Everyday social comparisons between romantic partners.

The authors examined the frequency, direction, and impact of social comparisons between romantic partners. Comparisons were expected to occur on a daily basis, owing to regular interactions between partners. To the extent that one empathizes and shares outcomes with one's partner, one might respond more positively to upward than to downward comparisons. Study 1a was an experience-sampling study in which participants reported comparisons made to their spouse over 2 weeks. Study 1b examined reactions to the most significant comparisons made during the experience-sampling study. Participants reported making comparisons to their romantic partner more than once a day on average and experienced more positive responses to upward than to downward comparisons. Study 2 demonstrated that participants empathized and shared outcomes with their partner to a greater extent than with a friend. Study 3 confirmed that participants responded more positively to upward than to downward comparisons even for domains high in self-relevance and even when the comparison had negative self-evaluative implications. These results suggest that, owing to higher levels of empathy and shared fate with partners, comparisons function differently in romantic than in other relationships. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interruption management in the intensive care unit: Predicting resumption times and assessing distributed support.

Interruptions are frequent in many work domains. Researchers in health care have started to study interruptions extensively, but their studies usually do not use a theoretically guided approach. Conversely, researchers conducting theoretically rich laboratory studies on interruptions have not usually investigated how effectively their findings account for humans working in complex systems such as intensive care units. In the current study, we use the memory for goals theory and prospective memory theory to investigate which properties of an interruption influence how long it takes nurses to resume interrupted critical care tasks. We collected data with a mobile eye tracker in an intensive care unit and developed multiple regression models to predict resumption times. In 55.8% of all interruptions there was a finite—and therefore analyzable—resumption lag. For these cases, the main regression model explained 30.9% (adjusted R2) of the variance. Longer interruptions (β = .36, p p