The timekeeping of Egyptian outflow clocks

Simple as the outflow clock principle may seem for the measurement of time, its translation into an accurate clock raises formidable technical and conceptual problems. An attempt is made here to reconstruct the Egyptians' consciousness of these problems, and the success of their solutions.     

Examining the accuracy of teachers' judgments of DIBELS performance

The purpose of this investigation was to examine the accuracy of teachers' judgments of students' early literacy skills and to determine if students' achievement levels influenced teachers' judgments. Typical and lower‐achieving kindergarten and first‐grade students' scores on the Nonsense Word Fluency and Phoneme Segmentation Fluency measures of the Dynamic Indicators of Basic Early Literacy Skills (DIBELS) were compared to the predicted performance by their teachers. Results showed a moderately strong correlation between teachers' judgments and students' performance across all of the students, which is consistent with past research. Teachers' judgments, however, consistently and significantly overestimated the actual performance of students, particularly those who were typically performing students. The findings of the investigation suggest that relying on teachers' judgments of students' early literacy skills alone may be insufficient to accurately identify students at risk for reading difficulties. © 2011 Wiley Periodicals, Inc.     

VIII. THE SITUATION FOR CHILDREN WITHOUT PARENTAL CARE AND STRATEGIES FOR POLICY CHANGE

Research that clearly demonstrates the negative effects of institutionalization, particularly for young children, has been critical for changing policy. However, actually putting science into action requires advocacy, persistence, and perseverance. Policy makers and advocates must be informed about the research and use it effectively. This paper proposes a number of key components for translating research into policy and programs: analyzing the situation, using evidence to build the case for action, developing policies, building program capacity in child welfare and early childhood development, creating a family‐based child welfare system, and developing a system of monitoring and accountability. Much of the knowledge in this paper comes from experiences, desk reviews, and case studies of successful practices. Research provides the basis, but moving research to practice depends on collaboration between researchers who understand the key policy perspectives and policy makers who understand the research.     

Managing the Progressive Publishing Company During Market and Technology Transitions

As new media technologies and platforms emerge and take hold in our society, traditional publishers are wondering: What’s in this new content climate for me? The simple answer is: a lot. The digital world, mobile content delivery mechanisms and the public’s increasing comfort—even preference for—a media menu from which they can pick and choose what they want and how they want to receive it, brings exciting and potentially lucrative opportunities. For publishers who understand how to leverage their brand and create authentic, identifiable value in the eyes of the customer, risk can be reduced and new revenue streams built. Here are four best practices to position your publishing company for growth.     

Microfluidic wet spinning of chitosan-alginate microfibers and encapsulation of HepG2 cells in fibers

The successful encapsulation of human hepatocellular carcinoma (HepG2) cells would greatly assist a broad range of applications in tissue engineering. Due to the harsh conditions during standard chitosan fiber fabrication processes, encapsulation of HepG2 cells in chitosan fibers has been challenging. Here, we describe the successful wet-spinning of chitosan-alginate fibers using a coaxial flow microfluidic chip. We determined the optimal mixing conditions for generating chitosan-alginate fibers, including a 1:5 ratio of 2% (w∕w) water-soluble chitosan (WSC) solution to 2% (w∕w) alginate solution. Ratio including higher than 2% (w∕w) WSC solution increased aggregation throughout the mixture. By suspending cells in the WSC-alginate solution, we successfully fabricated HepG2 cell-laden fibers. The encapsulated HepG2 cells in the chitosan-alginate fibers were more viable than cells encapsulated in pure alginate fibers, suggesting that cross-linked chitosan provides a better environment for HepG2 cells than alginate alone. In addition, we found that the adhesion of HepG2 cells on the chitosan-alginate fiber is much better than that on the alginate fibers.     

Identifying the Content,Lesson Structure,and Data Use Within Pre-collegiate Data Science Curricula

Journal of Science Education and Technology - As data become more available and integrated into daily life, there has been growing interest in developing data science curricula for youth in...