A quantitative interaction analysis of an authentic CALL environment: New Dynamic English

This study describes second language learners\u27 use of interactional options (e.g., a glossary usage) within New Dynamic English, a listening-based computer-assisted language learning (CALL) program produced by DynEd International. The study then elaborates on the students\u27 use of options and how it relates to the students\u27 performances within the program and their second language (L2) learning. Student choices in an interactive multimedia environment and modification of input are discussed. Results from this study, though they conflict with past research, have important implications for future L2 teachers and researchers in second language acquisition (SLA) and CALL. This study was performed in an authentic learning environment and points out the benefits, drawbacks, and the need for much more authentic learning research

Fast iterative solvers for geomechanics in a commercial FE code

There is a pressing need to improve the feasibility of three-dimensional finite element (FE) methods applied to many problems in civil engineering. This is particularly the case for static analyses in geotechnical engineering: ideally, models would be 3D, follow the actual geometry, use non-linear material formulations and allow simulation of construction sequences, and all of this with a reasonable degree of accuracy. One major obstacle to improvements in this regard is the difficulty in solving of the set of (linearised) algebraic equations which arises from a typical discretisation approach. Very large systems become cumbersome for direct techniques to solve economically. This paper describes the incorporation of iterative (rather than direct) solution techniques, developed through University research, into commercial FE software for geotechnics

Analytical evaluation of effect of equivalence ratio inlet-air temperature and combustion pressure on performance of several possible ram-jet fuels

The results of an analytical investigation of the theoretical air specific impulse performance and adiabatic combustion temperatures of several possible ram-jet fuels over a range of equivalence ratios, inlet-air temperatures, and combustion pressures, is presented herein. The fuels include octane-1, 50-percent-magnesium slurry, boron, pentaborane, diborane, hydrogen, carbon, and aluminum. Thermal effects from high combustion temperatures were found to effect considerably the combustion performance of all the fuels. An increase in combustion pressure was beneficial to air specific impulse at high combustion temperatures. The use of these theoretical data in engine operation and in the evaluation of experimental data is described

Strategic Implications of Data Gathering Activities in Small Firms: A Comparison Between Family and Nonfamily Firms

The empirical research presented in this article examines data gathering activities  and processes of small businesses and compares those activities and processes in family and nonfamily firms. MANOVA and t-test analyses  were  used  in analyzing questionnaire  data from 1245 respondents in 89 small businesses. For these small firms, the results indicated differences in the relative use of types of information gathered and processes used. Further, the study found differences between family and nonfamily firm data gathering activities and processes  used.  Finally, the study indicated that the type of customer to whom a firm sold had an impact on the data gathering activities of a small business and  impacted family  and nonfamily firm  data gathering differentially

Theoretical Combustion Performance of Several High-Energy Fuels for Ramjet Engines

An analytical evaluation of the air and fuel specific-impulse characteristics of magnesium, magnesium octene-1 slurries, aluminum, aluminum octene-1 slurries, boron, boron octene-1 slurries, carbon, hydrogen, alpha-methylnaphthalene, diborane, pentaborane, and octene-1 is presented. While chemical equilibrium was assumed in the combustion process, the expansion was assumed to occur at fixed composition

Tn-Seq reveals hidden complexity in the utilization of host-derived glutathione in \u3cem\u3eFrancisella tularensis\u3c/em\u3e

Host-derived glutathione (GSH) is an essential source of cysteine for the intracellular pathogen Francisella tularensis. In a comprehensive transposon insertion sequencing screen, we identified several F. tularensis genes that play central and previously unappreciated roles in the utilization of GSH during the growth of the bacterium in macrophages. We show that one of these, a gene we named dptA, encodes a proton-dependent oligopeptide transporter that enables growth of the organism on the dipeptide Cys-Gly, a key breakdown product of GSH generated by the enzyme γ-glutamyltranspeptidase (GGT). Although GGT was thought to be the principal enzyme involved in GSH breakdown in F. tularensis, our screen identified a second enzyme, referred to as ChaC, that is also involved in the utilization of exogenous GSH. However, unlike GGT and DptA, we show that the importance of ChaC in supporting intramacrophage growth extends beyond cysteine acquisition. Taken together, our findings provide a compendium of F. tularensis genes required for intracellular growth and identify new players in the metabolism of GSH that could be attractive targets for therapeutic intervention

(S)-N-(2,5-Dimethylphenyl)-1-(quinoline-8-ylsulfonyl)pyrrolidine-2-carboxamide as a Small Molecule Inhibitor Probe for the Study of Respiratory Syncytial Virus Infection

A high-throughput, cell-based screen was used to identify chemotypes as inhibitors for human respiratory syncytial virus (hRSV). Optimization of a sulfonylpyrrolidine scaffold resulted in compound 5o that inhibited a virus-induced cytopathic effect in the entry stage of infection (EC50 = 2.3 ± 0.8 µM) with marginal cytotoxicity (CC50 = 30.9 ± 1.1 µM) and reduced viral titer by 100-fold. Compared to ribavirin, sulfonylpyrrolidine 5o demonstrated an improved in vitro potency and selectivity index