Long-delay,one-trial conditioned preference and retention in monkeys (Cebus apella)

Cebus monkeys explored a small T-maze for 5 min, and their preference for the striped or black arm of the maze was assessed. On the next day, the experimental animals were placed into the nonpreferred arm for a 1-min period (exposure to the CS), removed from the T-maze for a 30-min delay interval, and then returned to the startbox of the maze, where they received a food reward (UCS). One control group (CS only) received the placement experience but was not rewarded after the 30-min period. A second control group (noncontingent UCS) received the reward in the startbox but not the placement experience. A second preference test showed that the experimental, but not the control, animals reversed their original preference, now showing a preference for the arm associated with reward. A retention test given 4 months after three such training-test trials revealed considerable retention of the preferences exhibited by the experimental and CS-only control subjects.     

Development of occupational aspirations in early Korean adolescents: a multiple-group latent curve model analysis

The complex phenomenon of intraindividual and interindividual differences in the development of occupational aspirations and factors influencing this development were examined in a longitudinal sample of 5,727 Korean adolescents over a 4-year period. A downward trajectory of occupational aspirations from junior high school to the first year of high school was found. Rate of change in expressed aspirations was different for men and women. Potentially important initial differences in occupational aspirations development, based on curriculum track, were also detected.     

Fixing Special Education

The current system of educating disabled students provides financial incentives to schools to overidentify students as disabled and underserve those that are identified. The incentive to overidentify is caused by providing schools with additional funds as more students are placed in special education categories that are ambiguous to diagnose and require relatively low additional expenditures to address. The incentive to underserve is caused by high information and transaction costs imposed on parents using the legal process to obtain desired services. An efficient alternative to the current system is to offer disabled students vouchers worth the cost of their education in public schools with which they can attend a private school if they wish. This article considers empirical analyses of the relationship between financial incentives and overidentification as well as the potential benefits of vouchers for special education. It concludes that vouchers for special education are a promising idea for improving the quality of education for disabled students while constraining growth in special education enrollments.     

On the Subject of English

Assiduous readers of English for Ages 5 to 16 may remember that, in their introductory section, Professor Cox's Working Group identify five "views" of the role of English in the curriculum: "cultural heritage", "personal growth", "cultural analysis", "adult needs", and "cross-curricular". In this article, Jay Snow discusses these views, relating them to the history of English and to its potential future development.     

Peer Problems and Hyperactivity–Impulsivity Among Norwegian and American Children: The Role of 5‐HTTLPR

Peer problems are linked to attention deficit hyperactivity disorder (ADHD) symptoms and the serotonin system is thought to be involved in ADHD‐related behavior. Hence, from a Gene × Environment perspective, the serotonin transporter 5‐HTTLPR may play a moderating role. In two large community samples, the moderating role of 5‐HTTLPR was examined related to more hyperactivity–impulsivity symptoms (HI symptoms) predicted by more peer problems. In Study 1, involving 642 Norwegian children, results indicated that for s‐allele carriers only, caregiver‐reported peer problems at age 4 predicted more parent‐reported HI symptoms at age 6. In Study 2, similar results emerged involving 482 American children. Discussion focuses on differential sensitivity to the adverse effects of poor peer relations.     

Microfluidic platform for isolating nucleic acid targets using sequence specific hybridization

The separation of target nucleic acid sequences from biological samples has emerged as a significant process in today''s diagnostics and detection strategies. In addition to the possible clinical applications, the fundamental understanding of target and sequence specific hybridization on surface modified magnetic beads is of high value. In this paper, we describe a novel microfluidic platform that utilizes a mobile magnetic field in static microfluidic channels, where single stranded DNA (ssDNA) molecules are isolated via nucleic acid hybridization. We first established efficient isolation of biotinylated capture probe (BP) using streptavidin-coated magnetic beads. Subsequently, we investigated the hybridization of target ssDNA with BP bound to beads and explained these hybridization kinetics using a dual-species kinetic model. The number of hybridized target ssDNA molecules was determined to be about 6.5 times less than that of BP on the bead surface, due to steric hindrance effects. The hybridization of target ssDNA with non-complementary BP bound to bead was also examined, and non-specific hybridization was found to be insignificant. Finally, we demonstrated highly efficient capture and isolation of target ssDNA in the presence of non-target ssDNA, where as low as 1% target ssDNA can be detected from mixture. The microfluidic method described in this paper is significantly relevant and is broadly applicable, especially towards point-of-care biological diagnostic platforms that require binding and separation of known target biomolecules, such as RNA, ssDNA, or protein.     

Lessons from Alternative Grading: Essential Qualities of Teacher Feedback

One critically important step in the instructional process is providing feedback to students, and yet, providing timely and thorough feedback is often lacking due attention. Reasons for this oversight could range from several factors including increased class sizes, vast content coverage requirements, extracurricular responsibilities, and the generally hectic daily schedules of teachers. This article synthesizes the findings from a year-long qualitative study investigating the alternative grading practices of five high school teachers and gives particular attention to the nature of the feedback these teachers provided to their students. Teachers' feedback is pared down to its essential qualities in order to offer manageable and practical strategies to current classroom teachers for providing effective feedback to their students.     

Theory Testing, Effect-Size Evaluation, and Differential Susceptibility to Rearing Influence: The Case of Mothering and Attachment

It is important to distinguish theory testing from effect-size evaluation when considering the impact of mothering on attachment security discerned in the De Wolff and van Ijzendoorn meta-analysis. Moreover, the possibility exists that this analysis both over- and underestimates mothering effects, as would be the case if infants vary in their susceptibility to rearing influence.     

Childhood Experience and the Onset of Menarche: A Test of a Sociobiological Model

We tested predictions about psychosocial factors in the onset of menarche using data from a longitudinal study of 16-year-old girls. Belsky, Steinberg, and Draper have proposed a model that seeks to explain individual differences in maturational timing in terms of stressful childhood experiences. Their model hypothesizes that (1) individuals who grow up under conditions of family stress (2) experience behavioral and psychological problems which (3) provoke earlier reproductive readiness. In this study, the effect of family stressors on menarche was mediated by neither behavior problems nor weight, contrary to the predictions. However, the most provocative proposition advanced by Belsky et al. received empirical support. Family conflict and father absence in childhood predicted an earlier age of menarche, and these factors in combination with weight showed some evidence of an additive influence on menarche. A genetic inheritance model may provide a more parsimonious account of these data than does a conditional adaptation model derived from sociobiology.     

Two forgotten elements of a knowledge management strategy

Knowledge Management Research & Practice - In reviewing the knowledge management (KM) literature, Guo & Sheffield (2008) show that KM research is part of the mainstream of information...