The use of a dynamic screening of phonological awareness to predict risk for reading disabilities in kindergarten children

This study examined the usefulness and predictive validity of a dynamic screening of phonological awareness in two samples of kindergarten children. In one sample (n = 90), the predictive validity of the dynamic assessment was compared to a static version of the same screening measure. In the second sample (n = 96), the dynamic screening measure was compared to a commonly used screening tool, Dynamic Indicators of Basic Early Literacy Skills Initial Sound Fluency. Results showed that the dynamic screening measure uniquely predicted end-of-year reading achievement and outcomes in both samples. These results provide preliminary support for the usefulness of a dynamic screening measure of phonological awareness for kindergarten students.     

The author as star

The rise of the “star” author and the cult of celebrity overwhelms publishing in the same way that it has movies and professional sports. Television creates the star system, agents nurture it. Publishers must find ways of surviving it. The Internet provides a means for star authors to reach their public without the intermediation of their publisher, but it is not yet a medium in which stars are born. Address for correspondence     

Issues of validity in science attitude measurement

This article explores the work that Moore and Foy (1997) did in revising and field testing the Scientific Attitude Instrument (SAI). I begin by showing that the empirical work with the revised instrument, the SAI II, raises doubts about the instrument's validity, and I suggest that these doubts seem to coincide rather remarkably with ones raised in an extensive study of science attitude instruments published in the early 1980s. I then consider the field testing of the SAI II in light of alternative approaches to validating instruments, and I show that the revisions made to the SAI leave its validity in question. I end by considering how we might develop guidelines for validating the instruments we use in science education research. J Res Sci Teach 34: 337–341, 1997.     

种质资源保护中的问题与挑战

本文对植物迁地保护,特别是种质资源保护的研究背景、科学问题、行动计划和保护策略进行了评述,重点讨论了种子库在保护植物多样性中面临的挑战和重要科学问题,特别是种子活力、种子寿命和超低温保存等问题。大量的实例和数据表明,种子库作为植物多样性保护的重要手段之一,其在资金投入、保存时间和保存效率方面远远高于就地保护和其它的迁地保护方法。     

Stable, biocompatible lipid vesicle generation by solvent extraction-based droplet microfluidics

In this paper, we present a microfluidic platform for the continuous generation of stable, monodisperse lipid vesicles 20–110 μm in diameter. Our approach utilizes a microfluidic flow-focusing droplet generation design to control the vesicle size by altering the system’s fluid flow rates to generate vesicles with narrow size distribution. Double emulsions are first produced in consecutive flow-focusing channel geometries and lipid membranes are then formed through a controlled solvent extraction process. Since no strong solvents are used in the process, our method allows for the safe encapsulation and manipulation of an assortment of biological entities, including cells, proteins, and nucleic acids. The vesicles generated by this method are stable and have a shelf life of at least 3 months. Here, we demonstrate the cell-free in vitro synthesis of proteins within lipid vesicles as an initial step towards the development of an artificial cell.