Near-field microscopy and lithography of light-emitting polymers

We describe the application of scanning near-field optical microscopy (SNOM) to the study of the photophysical and self-organization properties of thin films of blends of conjugated polymers, and also to the lateral nanoscale patterning of conjugated-polymer structures. Such thin-film plastic semiconductor nanostructures offer significant potential for use in opto-electronic devices. The implementation of SNOM we employ is the most established form in which a probe with a sub-wavelength aperture is scanned in close proximity to the sample surface. We consider the nature of the near-field optical distribution, which decays within the first ca. 100 nm of these semiconductor materials, and address the identification of topographic artefacts in near-field optical images. While the topographic information obtained simultaneously with optical data in any SNOM experiment enables an easy comparison with the higher-resolution tapping-mode atomic force microscopy, the spectroscopic contrast provided by fluorescence SNOM gives an unambiguous chemical identification of the different phases in a conjugated-polymer blend. Both fluorescence and photoconductivity SNOM indicate that intermixing of constituent polymers in a blend, or nanoscale phase separation, is responsible for the high efficiency of devices employing these materials as their active layer. We also demonstrate a scheme for nano-optical lithography with SNOM of conjugated-polymer structures, which has been employed successfully for the fabrication of poly(-phenylene vinylene) nanostructures with 160 nm feature sizes.     

Convectively driven polymerase chain reaction thermal cycler

We have fabricated a low-cost disposable polymerase chain reaction thermal chamber that uses buoyancy forces to move the sample solution between the different temperatures necessary for amplification. Three-dimensional, unsteady finite element modeling and a simpler 1-D steady-state model are used together with digital particle image velocimetry data to characterize the flow within the device. Biological samples have been amplified using this novel thermal chamber. Time for amplification is less than 30 min. More importantly, an analysis of the energy consumption shows significant improvements over current technology.     

"Development of Time, Speed, and Distance Concepts": Correction to Siegler and Richards.

Reports an error in the original article by Robert S. Siegler and D. Dean Richards (Developmental Psychology, 1979, Vol. 15[3], pp. 288-298). The column headings of Table 1 on p. 291 are incorrect. Each pair of lines in the column headings represents the starting points, stopping points, and total distance traveled by the trains. The corrected table appears below. (The following abstract of this article originally appeared in record 1979-28311-001.) Used the rule-assessment approach to examine understanding of the concepts of time, speed, and distance in 36 5-, 8-, and 11-yr-olds and 12 undergraduates. Parallel tasks were developed for the 3 concepts that allowed specification of whether Ss were relying on time, speed, distance, end point, end time, beginning point, or beginning time cues in making their judgments. It was found that 5-yr-olds understood all 3 concepts in the same way: Whichever train ended farther ahead on the tracks was said to have traveled for the longer time, at the faster speed, and for the greater distance. Undergraduates, at the other extreme, understood all 3 concepts as distinct and separate ideas. The transitional period was marked by specific confusions among the 3 concepts: Time was regularly confused with distance, distance was confused with time, and speed was confused with distance and to some extent with end point. Both speed and distance concepts appeared to be mastered well before the concept of time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Catalyst Systems in Anionic Copolymerisations

The paper considers three areas of current interest in anionic polymerisation. Firstly, the factors governing the efficiencies of initiation of anionic electron transfer catalysts are discussed, and the differences between the initiation mechanism of this class of catalysts and that of alkali metals are highlighted. Secondly, the problems relating to the synthesis of telechelic polydienes of high 1,4 content by an anionic technique are examined in relation to the contradictory claims of recent authors. Finally an account is given of the present position in developing transformation reactions to prepare novel block copolymers.     

Cognitive and learning difficulties and how they affect access to IT systems

In October 2005, the IBM Human Ability and Accessibility Center and T.J. Watson Research Center hosted a symposium on “cognitive and learning difficulties and how they affect access to IT systems”. The central premise of the symposium was the recognition that cognitive and learning difficulties have a profound impact on a person’s ability to interact with information technology (IT) systems, but that little support is currently being offered by those systems. By bringing together internationally renowned experts from a variety of different, but complementary, research fields, the symposium aimed to provide a complete overview of the issues related to this topic. This paper summarises the discussions and findings of the symposium.     

Using Semantic Web Technologies to Analyze Learning Content

The authors demonstrate how to use semantic Web technologies to improve the state-of-the-art in online learning environments and bridge the gap between students on the one hand, and authors or teachers on the other. The ontological framework presented here helps formalize learning object context as a complex interplay of different learning-related elements and shows how we can use semantic annotation to interrelate diverse learning artifacts. On top of this framework, the authors implemented several feedback channels for educators to improve the delivery of future Web-based courses.     

Internet vs. paper and pencil administration of questionnaires commonly used in panic/agoraphobia research

The aim of this study was to investigate the psychometric properties of Internet administered questionnaires used in panic research. Included were 494 people who had registered for an Internet-based treatment program for panic disorder (PD). Participants were randomly assigned to fill in the questionnaires either on the Internet or the paper-and-pencil versions, and then to fill in the same questionnaires again the next day using the other format. The questionnaires were the body sensations questionnaire [BSQ; Chambless, D. L., Caputo, G. C., Bright, P., & Gallagher, R. (1984). Assessment of fear of fear in agoraphobics: the body sensations questionnaire and the agoraphobic cognitions questionnaire. Journal of Consulting and Clinical Psychology, 52, 1090–1097], agoraphobic cognitions questionnaire [ACQ; Chambless, D. L., Caputo, G. C., Bright, P., & Gallagher, R. (1984). Assessment of fear of fear in agoraphobics: the body sensations questionnaire and the agoraphobic cognitions questionnaire. Journal of Consulting and Clinical Psychology, 52, 1090–1097], mobility inventory [MI; Chambless, D. L., Caputo, G., Jasin, S., Gracely, E. J., & Williams, C. (1985). The mobility inventory for agoraphobia. Behaviour Research and Therapy, 23, 35–44], beck anxiety inventory [BAI; Beck, A. T., Epstein, N., Brown, G., & Steer, R. A. (1988). An inventory for measuring clinical anxiety: psychometric properties. Journal of Consulting and Clinical Psychology, 56, 893–897], beck depression inventory II [Beck, A. T., & Steer, R. A. (1996). Beck Depression Inventory. Manual, Svensk version (Swedish version). Fagernes, Norway: Psykologiförlaget, AB], quality of life inventory [QOLI; Frisch, M. B., Cornell, J., Villanueva, M., & Retzlaff, P. J. (1992). Clinical validation of the quality of life inventory. A measure of life satisfaction for use in treatment planning and outcome assessment. Psychological Assessment, 4, 92–101], and montgomery Åsberg depression rating scale [MADRS; Svanborg, P., & Åsberg, M. (1994). A new self-rating scale for depression and anxiety states based on the comprehensive psychopathological rating scale. ACTA Psychiatrica Scandinavica, 89, 21–28]. Results showed largely equivalent psychometric properties for the two administration formats (Cronbach’s α between 0.79 and 0.95). The results also showed high and significant correlations between the Internet and the paper-and-pencil versions. Analyses of order effects showed an interaction effect for the BSQ and the MI (subscale Accompanied), a main effect was identified for ACQ, MI-Alone, BAI and BDI II. However, in contrast to previous research, the Internet version did not consistently generate higher scores and effect sizes for the differences were generally low. Given the presence of an interaction effect, we recommend that the administration format should be stable in research across measurement points. Finally, the findings suggest that Internet versions of questionnaires used in PD research can be used with confidence.