A microfluidic platform for measuring electrical activity across cells

In this paper, we present a microfluidic chip that is capable of measuring electrical conductance through gap junction channels in a 2-dimensional cell sheet. The chip utilizes a tri-stream laminar flow to create a non-conductive sucrose gap between the two conducting solutions so that electrical current can pass across the sucrose gap only through the cells. Using the chip, we tested the effect of a gap junction inhibitor, 2-APB, on the electrical coupling of connexin 43 (Cx43) gap junction channels in NRK-49F cells. We found that 2-APB reversibly blocks the conductivity in a dose-dependent manner. The tri-stream chip further allows us to simultaneously follow the conductance changes and dye diffusion in real time. We show that 2-APB affects both conductance and diffusion, supporting the interpretation that both sets of data reflect the same gap junction activity. The chip provides a generic platform to investigate gap junction properties and to screen drugs that may inhibit or potentiate gap junction transmission.     

Texts after Community: The Case of Czechs in America

The article discusses the various types of texts produced by the Czech immigrant community in the United States in the nineteenth century. An interesting example is the periodical Hospodá?. The author lists some bibliographies and directories that researchers can consult in order to locate such material, but much of it remains either unknown, difficult to access, or both. Buildings can also be considered texts. He urges librarians, archivists, and scholars of sources to work more with these materials.     

名辩逻辑提纲(上)

构建中国逻辑的横向体系,编写出教科书式的中国逻辑读本,是一项极具意义的学术工程。《提纲》乃这方面的闯新之作,计有“绪论”“概念”“辩说”“余论”四章。“概念”“辩说”叙说中国逻辑的两大支柱部分;“绪论”“余论”阐述中国逻辑的总体、总貌和特色     

Perspectives of students with autism on their participation in a peer-mediated intervention

The article describes research into the perspectives of students with autism regarding their participation as the target participants in a peer-mediated social communication intervention. Questionnaires were administered to four elementary-aged students with autism before and after their involvement in the intervention. The students' parents and teachers also completed questionnaires about the students' participation in the intervention. Through the use of these questionnaires, we gained an insight into students' experiences with the intervention, which elements of the intervention they found most enjoyable and most effective, and the perceived impacts of the intervention on their social communication behaviours. Qualitative and quantitative analyses of the questionnaire data revealed that all four students with autism enjoyed participating in the peer-mediated intervention sessions, felt that their social communication behaviours had improved as a result of their involvement, and would like to be involved in similar sessions in the future. Implications for parents and educators who support the social communication of children with autism are explored.     

A simple method for assessment of muscle force,velocity, and power producing capacities from functional movement tasks

A range of force (F) and velocity (V) data obtained from functional movement tasks (e.g., running, jumping, throwing, lifting, cycling) performed under variety of external loads have typically revealed strong and approximately linear F–V relationships. The regression model parameters reveal the maximum F (F-intercept), V (V-intercept), and power (P) producing capacities of the tested muscles. The aim of the present study was to evaluate the level of agreement between the routinely used “multiple-load model” and a simple “two-load model” based on direct assessment of the F–V relationship from only 2 external loads applied. Twelve participants were tested on the maximum performance vertical jumps, cycling, bench press throws, and bench pull performed against a variety of different loads. All 4 tested tasks revealed both exceptionally strong relationships between the parameters of the 2 models (median R = 0.98) and a lack of meaningful differences between their magnitudes (fixed bias below 3.4%). Therefore, addition of another load to the standard tests of various functional tasks typically conducted under a single set of mechanical conditions could allow for the assessment of the muscle mechanical properties such as the muscle F, V, and P producing capacities.     

Electronic Theses and Dissertations Initiatives: A Survey of University Libraries in Nigeria

The study investigated the extent of adoption of electronic theses and dissertations in university libraries in Nigeria. Data collection for the study was via online questionnaire. The study revealed that digitization of theses and dissertations started between 1980 and 1995. It was found that only a few university libraries have embraced digitization of theses and dissertations in Nigeria. Benefits of electronic theses and dissertations were identified as improving university ranking and visibility, increasing access to the theses and dissertations, saving space in the library, enabling others link to the work with persistent URLs, preserving the work for future generations, and saving costs for students. Challenges such as unstable internet connectivity, lack of funding, irregular power supply, lack of information technology personnel, absence of electronic theses and dissertations submission policy, and copyright issues were identified. It is hoped that the study might provide insights useful for librarians planning to embark on the digitization of theses and dissertations project.     

从审稿者年龄与审稿意见看审稿队伍建设

探讨审稿者年龄对审稿质量是否有影响。对64期中华系列杂志巳刊发论文的4060份审稿意见，按A组（审高者35-49岁）和B组（50岁以上）2组分别进行分类整理。结果为不同年龄组对审稿侧重点不完全相同：在设计方法及提出修改意见方面，A组提出的建议较B组少，而在对统计学方法提出修改建议以及对参考文献进行审核方面，A组提出的建议较B组多。提示应该大胆启用年轻的审稿专家，从而可以使审稿队伍趋于年轻化。     

The effects of baseball bat mass properties on swing mechanics,ground reaction forces,and swing timing

Swing trajectory and ground reaction forces (GRF) of 30 collegiate baseball batters hitting a pitched ball were compared between a standard bat, a bat with extra weight about its barrel, and a bat with extra weight in its handle. It was hypothesised that when compared to a standard bat, only a handle-weighted bat would produce equivalent bat kinematics. It was also hypothesised that hitters would not produce equivalent GRFs for each weighted bat, but would maintain equivalent timing when compared to a standard bat. Data were collected utilising a 500 Hz motion capture system and 1,000 Hz force plate system. Data between bats were considered equivalent when the 95% confidence interval of the difference was contained entirely within ±5% of the standard bat mean value. The handle-weighted bat had equivalent kinematics, whereas the barrel-weighted bat did not. Both weighted bats had equivalent peak GRF variables. Neither weighted bat maintained equivalence in the timing of bat kinematics and some peak GRFs. The ability to maintain swing kinematics with a handle-weighted bat may have implications for swing training and warm-up. However, altered timings of kinematics and kinetics require further research to understand the implications on returning to a conventionally weighted bat.