Memory capacity, selective control, and value-directed remembering in children with and without attention-deficit/hyperactivity disorder (ADHD).

Objective: The ability to select what is important to remember, to attend to this information, and to recall high-value items leads to the efficient use of memory. The present study examined how children with and without attention-deficit/hyperactivity disorder (ADHD) performed on an incentive-based selectivity task in which to-be-remembered items were worth different point values. Method: Participants were 6–9 year old children with ADHD (n = 57) and without ADHD (n = 59). Using a selectivity task, participants studied words paired with point values and were asked to maximize their score, which was the overall value of the items they recalled. This task allows for measures of memory capacity and the ability to selectively remember high-value items. Results: Although there were no significant between-groups differences in the number of words recalled (memory capacity), children with ADHD were less selective than children in the control group in terms of the value of the items they recalled (control of memory). All children recalled more high-value items than low-value items and showed some learning with task experience, but children with ADHD Combined type did not efficiently maximize memory performance (as measured by a selectivity index) relative to children with ADHD Inattentive type and healthy controls, who did not differ significantly from one another. Conclusions: Children with ADHD Combined type exhibit impairments in the strategic and efficient encoding and recall of high-value items. The findings have implications for theories of memory dysfunction in childhood ADHD and the key role of metacognition, cognitive control, and value-directed remembering when considering the strategic use of memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

NXP单芯片方案再掀低成本手机浪潮

恩智浦半导体(NXP Semiconductors)推出面向"超低成本(ULC)"手机细分市场的Nexperia PNX4903 GSM/GPRS优化多媒体解决方案.PNX4903在一个单片集成电路上实现系统级的完全操作,提供高集成度和性能,使手机OEM/ODM能够在一个可靠、低成本、低能耗的整体方案中为入门级手机用户提供丰富的多媒体内容.     

The study of youth online: a critical review and agenda

The increasing and pervasive use of online technologies, especially social media, has inspired scholars to investigate how the Internet influences communication. As young people represent the fastest growing adopters of new online technology, much of this research targets youth activity online. But how is the communication discipline taking up this issue, broadly? Typically left to new media and computer-mediated communication scholars, we argue youth online activity raises new and exciting possibilities for researchers across the communication discipline. In this paper, we present a qualitative content analysis of communication research about youth and the Internet. Our analysis of over 700 journal articles provides a clear picture of past and present trends in communication research of youth online activity. Furthermore, we discuss the top four content themes, including: uses and gratifications, engagement, identity, and the uniqueness of youth experience. Critically, we articulate how such research organizes and positions youth in meaningful ways, paving the way for issues of inclusion. We call for a shift from a “difference” framework to one that more explicitly considers “complexity” before suggesting opportunities for future research that crosses and unites subdisciplinary boundaries.     

Imaging performance of A-PET: a small animal PET camera

The evolution of positron emission tomography (PET) imaging for small animals has led to the development of dedicated PET scanner designs with high resolution and sensitivity. The animal PET scanner achieves these goals for imaging small animals such as mice and rats. The scanner uses a pixelated Anger-logic detector for discriminating 2 x 2 x 10 mm3 crystals with 19-mm-diameter photomultiplier tubes. With a 19.7-cm ring diameter, the scanner has an axial length of 11.9 cm and operates exclusively in three-dimensional imaging mode, leading to very high sensitivity. Measurements show that the scanner design achieves a spatial resolution of 1.9 mm at the center of the field-of-view. Initially designed with gadolinium orthosilicate but changed to lutetium- yttrium orthosilicate, the scanner now achieves a sensitivity of 3.6% for a point source at the center of the field-of-view with an energy window of 250-665 keV. Iterative image reconstruction, together with accurate data corrections for scatter, random, and attenuation, are incorporated to achieve high-quality images and quantitative data. These results are demonstrated through our contrast recovery measurements as well as sample animal studies.     

The Symbiotic Sustainability Model: Conceptualizing NGO–Corporate Alliance Communication

We introduce the Symbiotic Sustainability Model (SSM) as a macrolevel explanation of nongovernmental organization (NGO)–corporate alliances. The SSM presents NGO–corporate alliances as distinct interorganizational communication relationships, symbolized to stakeholders to influence the mobilization of capital. We contend that alliance partners communicatively co‐construct the alliance with stakeholders in order to mobilize economic, social, cultural, and political capital. By focusing on the communication of alliances' existence and character, new propositions emerge concerning the role of communication, capital mobilization resulting from NGO–corporate alliances, NGOs and corporations' choice(s) of alliance partner(s), the number of partners with whom organizations are likely to communicate, and potential risks and rewards. The model is illustrated using the Rainforest Alliance and Chiquita Better Banana program as an abbreviated case study.     

Children's Fright Reactions to Television News

In a random survey of parents of kindergarten, second, fourth, and sixth grade children, 37% of the children were reported to have been frightened or upset by a news story on television. The percentage of children being frightened by news increased from kindergarten to the elementary school years, whereas the tendency to be frightened by fantastic, unreal content showed a decreasing trend. The top categories of stories producing fear were violence between strangers, foreign wars and famines, and natural disasters. me tendency to respond with fright to violence between strangers increased with age, and the tendency to be upset by natural disasters decreased with age. Proposed explanations for the observed age differences were based on developmental differences in children's understanding of the fantasy-reality distinction and in their responsiveness to perceptually salient stimuli.     

Free Energy Control of Charge Photogeneration in Polythiophene/Fullerene Solar Cells: The Influence of Thermal Annealing on P3HT/PCBM Blends

The function of organic solar cells is based upon charge photogeneration at donor/acceptor heterojunctions. In this paper, the origin of the improvement in short circuit current of poly(3‐hexylthiophene)/6,6‐phenyl C₆₁‐butyric acid methyl ester (P3HT/PCBM) solar cells with thermal annealing is examined. Transient absorption spectroscopy is employed to demonstrate that thermal annealing results in an approximate two‐fold increase in the yield of dissociated charges. The enhanced charge generation is correlated with a decrease in P3HT's ionization potential upon thermal annealing. These observations are in excellent quantitative agreement with a model in which efficient dissociation of the bound radical pair into free charges is dependent upon the bound radical state being thermally hot when initially generated, enabling it to overcome its coulombic binding energy. These observations provide strong evidence that the lowest unoccupied molecular orbital (LUMO) level offset of annealed P3HT/PCBM blends may be only just sufficient to drive efficient charge generation in polythiophene‐based solar cells. This has important implications for current strategies to optimize organic photovoltaic device performance based upon the development of smaller optical bandgap polymers.     

便携式无线产品的电池燃料量测

在无线通信领域中,可靠的电池电源正在从仅仅是一种便利转变为重要的必需品,因为越来越多的人在以笔记本电脑或蜂窝电话作为主要的通信工具.对于无线设备制造商而言,电池燃料量测长期以来一直是一个平衡处理过程.制造商们一致认为某些种类的量测是必不可少的,但不同的产品需采取特定的精度-一成本折衷方案.     

欧胜推出AudioPlus新产品线

10月15日,欧胜微电子有限公司宣布推出其AudioPlus电源管理产品线的第一款产品WM8350.该芯片将高保真音频编码解码器(CODEC)与电源管理子系统结合,可为便携式音频和导航应用提供高性能音频、同时延长电池寿命并降低系统成本.