Reading skill as a source of individual differences in the processing of instructional texts.

Evidence was found in support of the hypothesis that skilled readers are more likely than less skilled readers to successfully retrieve an appropriate procedure by reading an instructional text. Subjects completed a standardized reading comprehension test and a test designed to reflect their processing of an instructional text and an example. The instructional text and the example either described the same procedure for answering test items (no conflict) or described different and mutually exclusive procedures (conflict). Subjects who had higher scores on the reading test were more likely to notice the conflict between the instructional text and the example, and those who noticed the conflict were more likely to use the instructional text. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The in Vitro Antiplasmodial and Antiproliferative Activity of New Ferrocene-Based α-Aminocresols Targeting Hemozoin Inhibition and DNA Interaction

The conjugation of organometallic complexes to known bioactive organic frameworks is a proven strategy revered for devising new drug molecules with novel modes of action. This approach holds great promise for the generation of potent drug leads in the quest for therapeutic chemotypes with the potential to overcome the development of clinical resistance. Herein, we present the in vitro antiplasmodial and antiproliferative investigation of ferrocenyl α-aminocresol conjugates assembled by amalgamation of the organometallic ferrocene unit and an α-aminocresol scaffold possessing antimalarial activity. The compounds pursued in the study exhibited higher toxicity towards the chemosensitive (3D7) and -resistant (Dd2) strains of the Plasmodium falciparum parasite than to the human HCC70 triple-negative breast cancer cell line. Indication of cross-resistance was absent for the compounds evaluated against the multi-resistant Dd2 strain. Structure-activity analysis revealed that the phenolic hydroxy group and rotatable σ bond between the α-carbon and NH group of the α-amino-o-cresol skeleton are crucial for the biological activity of the compounds. Spectrophotometric techniques and in silico docking simulations performed on selected derivatives suggest that the compounds show a dual mode of action involving hemozoin inhibition and DNA interaction via minor-groove binding. Lastly, compound 9 a , identified as a possible lead, exhibited preferential binding for the plasmodial DNA isolated from 3D7 P. falciparum trophozoites over the mammalian calf thymus DNA, thereby substantiating the enhanced antiplasmodial activity of the compounds. The presented research demonstrates the strategy of incorporating organometallic complexes into known biologically active organic scaffolds as a viable avenue to fashion novel multimodal compounds with potential to counter the development drug resistance.     

Word knowledge and working memory as predictors of reading skill.

Three measures of working memory capacity and three measures of word knowledge were used as predictors of three different measures of reading skill. The results demonstrated that the size of a reader's vocabulary and the speed of accessing it are independent of a "depth" measure of word knowledge and that reading comprehension, reading speed, and text inferencing ability are all independent measures of reading skill. A series of regression analyses were conducted to derive a causal model of the three reading performance measures. The results indicated that working memory efficiency during reading was related to comprehension, whereas a more passive working memory capacity measure was related to reading speed. Moreover, text inferencing ability was related only to word knowledge. We conclude that concepts such as "reading skill," "working memory," and "word knowledge" are multidimensional constructs that cannot be captured by a single variable. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Food wrenching and dodging: A neuroethological test of cortical and dopaminergic contributions to sensorimotor behavior in the rat.

Sensorimotor behavior in unilateral decorticate and unilateral dopamine-depleted rats was studied in a naturally occurring social interaction in which rats compete for food with relatively stereotyped species-typical responses. In the interaction a "robber" attempts to wrest food from a feeding "victim," which in turn protects the food by making rapid contralateral dodges. Hemidecortication abolished dodging to food wrenching attempts made by a rat approaching contralaterally to the lesion, so that the food was stolen, but recovery occurred between 15 and 60 days after surgery. Use of the side contralateral to the lesion to wrest food was moderately impaired, and recovery of food wresting was more rapid than recovery of dodging. Unilateral dopamine depletion produced dodging impairments to food-wresting attempts that were made both ipsilateral and contralateral to the side of the lesion, and the deficits endured over 60 test days. The food was frequently lost to food-wrenching attempts made contralateral to the lesion, whereas the direction of dodges to approaches ipsilateral to the lesion was reversed. Food wresting was also bilaterally impaired. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual differences in the efficiency of word recognition.

Examined the hypothesis that the attentional demands of word recognition covary with other measures of reading efficiency. Individual differences in efficiency were indexed by (1) speed and accuracy of lexical access, (2) obligatory activation of phonological codes, and (3) working memory capacity. The attentional demands of word recognition were measured with a dual-task technique. Ss performed naming and probe-detection tasks separately (single task) and in combination (dual task). The results showed that single-task to dual-task decrements in performance on the naming and probe tasks were predicted by measures of the speed and accuracy of lexical access, obligatory activation of phonological codes, and efficiency of working memory. These findings provide support for the widespread assumption that the attentional demands of basic reading processes are a source of individual differences in reading skill. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Challenging minds? Students’ perceptions of computer-based World Class Tests of problem solving

World Class Arena is a British government initiative to assess and develop the skills of gifted and talented children. Part of the strategy is to use computer-based tests. Students attempt tasks that require them to engage in higher-order problem solving, often in interactive, realistic, contexts. This study reports observations and interviews in schools. Students found tasks engaging and motivating, despite the unfamiliarity of the problem types and the challenging nature of the items. Students had no problems working with computers. They were sometimes distracted by attractive graphics, and sometimes used poor heuristics when attempting tasks. The study provides evidence that a computer environment can provide new ways to assess the problem solving skills of highly able students.     

Factors influencing the selection of university majors varying in mathematical content.

53 male and 58 female undergraduates completed an arithmetic test and a questionnaire on their mathematics background, perceived skill, interest, and affect toward math. Most women avoided majors that required even moderate amounts of math, even though they were as skilled at arithmetic as males and had taken equivalent amounts of math in high school. Ss who were anxious about math avoided majors that had moderate or high math requirements. Ss who were less skilled at arithmetic chose majors with fewer math requirements. Because gender and negative affect toward math contributed independently to choice of major, interventions to combat math anxiety could be valuable for both males and females. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thiazolidinedione-based PI3Kα inhibitors: an analysis of biochemical and virtual screening methods

A series of synthesized and commercially available compounds were assessed against PI3Kα for in vitro inhibitory activity and the results compared to binding calculated in silico. Using published crystal structures of PI3Kγ and PI3Kδ co-crystallized with inhibitors as a template, docking was able to identify the majority of potent inhibitors from a decoy set of 1000 compounds. On the other hand, PI3Kα in the apo-form, modeled by induced fit docking, or built as a homology model gave only poor results. A PI3Kα homology model derived from a ligand-bound PI3Kδ crystal structure was developed that has a good ability to identify active compounds. The docking results identified binding poses for active compounds that differ from those identified to date and can contribute to our understanding of structure-activity relationships for PI3K inhibitors.     

Elevated concentrations of 1-hydroxypyrene in schoolchildren during winter in Christchurch, New Zealand

Particulate air pollution is significantly elevated during the winter in Christchurch, New Zealand, largely attributable to use of wood burners for domestic home heating, topography, and meteorological conditions. Polycyclic aromatic hydrocarbons (PAHs) are a key component of airborne particulate matter (PM) and urinary 1-hydroxypyrene (1-OHP) has previously been used to assess exposure of people to PAHs. We examined urinary 1-OHP in Christchurch male non-smoking schoolchildren (12-18 yr) on two occasions after high pollution events (48 and 72 microg PM(10)/m(3) 24-h average) and two occasions during periods of low pollution (19 and 12 microg PM(10)/m(3)). Concentrations of urinary 1-OHP were significantly elevated in the students during high pollution events (median (mean+/-SD) 0.043 (0.051+/-0.032) and 0.042 (0.060+/-0.092) micromol OHP/mol creatinine respectively) compared with low pollution periods (median (mean+/-SD) 0.019 (0.026+/-0.032) and 0.025 (0.028+/-0.018) micromol/mol creatinine respectively). The observed 1-OHP concentrations are at the lower end of those determined in children and non-occupationally exposed adults in international studies and suggest a generally low exposure to PAHs. The increased urinary 1-OHP concentrations following nights of elevated particulate concentrations in ambient air suggest increased exposure to ambient air pollution during winter time, and could potentially be used as a biomarker of exposure in this population.     

Does a relationship exist between body weight, concerns about weight, and smoking among adolescents? An integration of the literature with an emphasis on gender.

It has been speculated that body weight and concern about body weight are important factors in initiation of tobacco use among adolescents, particularly females. An examination of studies that have explored these relationships can provide important information on possible underlying mechanisms that could be used for prevention interventions. This review summarizes recent studies examining weight concerns and youth smoking, with a focus on gender differences. These studies were integrated with the few studies that have examined the relationship between actual body weight and smoking among adolescents. A total of 55 primary research articles met inclusion criteria for the review. Of these, 19 studies assessed the relationship between body weight and smoking, and 50 studies addressed weight concerns and smoking. Some evidence indicated a positive relationship between smoking and body weight among adolescents, although not all studies found a positive association. In terms of the relationship between weight concerns and adolescent smoking, the amount of evidence supporting a positive association differed depending on the dimension of weight concern considered, with the strongest evidence for dieting behaviors. For dieting behaviors, disordered eating symptoms, and some aspects of general weight concerns, the positive relationship with smoking was more consistent among female adolescents than among male adolescents. Possible explanations for these findings are discussed, and priorities for future research are identified.