College students' prevalence and perceptions of text messaging while driving

By analyzing self-reports from sample of 91 college students from the United States who are frequent drivers, the present study examined the prevalence of text messaging (or “texting”) while driving and the incidence of recklessness and consequences that accompany this behavior. Analyses revealed that 91% of participants reported having used text messaging while driving, with many reporting doing so with passengers, including children, riding in their vehicles. Further, a substantial number of participants reported driving dangerously above the speed limit and drifting into other traffic lanes while texting, and many reported “sexting” and arguing via text messages while driving. However, these young drivers agreed that texting while driving is dangerous and should be illegal. These results and the limitations to the present study are discussed.     

Evaluation methodology and metrics employed to assess the TRANSTAC two-way,speech-to-speech translation systems

One of the most difficult challenges that military personnel face when operating in foreign countries is clear and successful communication with the local population. To address this issue, the Defense Advanced Research Projects Agency (DARPA) is funding academic institutions and industrial organizations through the Spoken Language Communication and Translation System for Tactical Use (TRANSTAC) program to develop practical machine translation systems. The goal of the TRANSTAC program is to demonstrate capabilities to rapidly develop and field free-form, two-way, speech-to-speech translation systems that enable speakers of different languages to communicate with one another in real-world tactical situations without an interpreter. Evaluations of these technologies are a significant part of the program and DARPA has asked the National Institute of Standards and Technology (NIST) to lead this effort. This article presents the experimental design of the TRANSTAC evaluations and the metrics, both quantitative and qualitative, that were used to comprehensively assess the systems’ performance.     

Theoretical considerations of tissue electroporation with high-frequency bipolar pulses

This study introduces the use of high-frequency pulsed electric fields for tissue electroporation. Through the development of finite element models and the use of analytical techniques, electroporation with rectangular, bipolar pulses is investigated. The electric field and temperature distribution along with the associated transmembrane potential development are considered in a heterogeneous skin fold geometry. Results indicate that switching polarity on the nanosecond scale near the charging time of plasma membranes can greatly improve treatment outcomes in heterogeneous tissues. Specifically, high-frequency fields ranging from 500 kHz to 1 MHz are best suited to penetrate epithelial layers without inducing significant Joule heating, and cause electroporation in underlying cells.     

Potential for Passive Treatment of Coal Mine-derived Acid Mine Drainage in Abandoned Stream Channels

Mine Water and the Environment - Passive treatment of coal mining derived acid mine drainage (AMD) utilizes natural processes to neutralize acidity and remove dissolved metal contaminants. In some...     

Mechanistic and catalytic studies of β‐nitroalcohol crosslinking with polyamine

β‐Nitroalcohols (βNAs) are promising corneoscleral crosslinking agents for the treatment of diseases such as keratoconus and myopia. Although it is believed that formaldehyde is released from the crosslinking reactions of βNAs, the mechanism by which βNAs react with amine‐functionalized polymers has yet to be known. In this study, we present the reaction mechanism of the βNA crosslinking. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) data provide strong evidence that formaldehyde is released during the reaction. Catalytic studies show that sodium bicarbonate (NaHCO₃) and salmon testes DNA accelerate the reaction while hydroxynitrile lyase from Arabidopsis thaliana decelerates the crosslinking reaction. These results suggest that βNAs are potential self‐administered crosslinking agents for future clinical use. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Sequestration of AS-DACA into Acidic Compartments of the Membrane Trafficking System as a Mechanism of Drug Resistance in Rhabdomyosarcoma

The accumulation of weakly basic drugs into acidic organelles has recently been described as a contributor to resistance in childhood cancer rhabdomyosarcoma (RMS) cell lines with differential sensitivity to a novel topoisomerase II inhibitor, AS-DACA. The current study aims to explore the contribution of the endocytic pathway to AS-DACA sequestration in RMS cell lines. A 24-fold differential in AS-DACA cytotoxicity was detected between the RMS lines RD and Rh30. The effect of inhibitors of the endocytic pathway on AS-DACA sensitivity in RMS cell lines, coupled with the variations of endosomal marker expression, indicated the late endosomal/lysosomal compartment was implicated by confounding lines of evidence. Higher expression levels of Lysosomal-Associated Membrane Protein-1 (LAMP1) in the resistant RMS cell line, RD, provided correlations between the increased amount and activity of these compartments to AS-DACA resistance. The late endosomal inhibitor 3-methyladenine increased AS-DACA sensitivity solely in RD leading to the reduction of AS-DACA in membrane trafficking organelles. Acidification inhibitors did not produce an increase in AS-DACA sensitivity nor reduce its sequestration, indicating that the pH partitioning of weakly basic drugs into acidic compartments does not likely contribute to the AS-DACA sequestering resistance mechanism evident in RMS cells.     

Solid localization marker for MR imaging

A solid, stable material that can be easily cut into unique, identifiable shapes was compared with other localization markers used in magnetic resonance imaging to determine relaxation characteristics and chemical shift. The solid marker and the conventional oil-based markers caused substantial chemical shift artifacts and so should never be used when high levels of spatial accuracy are necessary, such as in stereotaxy. Although it had the lowest T2 of all the substances tested, the solid marker was useful in identifying structures when different coils, sequences, and fields of view were used.     

Asynchronous analysis of parallel dynamic programming algorithms

We examine a very simple asynchronous model of parallel computation that assumes the time to compute a task is random, following some probability distribution. The goal of this model is to capture the effects of unpredictable delays on processors, due to communication delays or cache misses, for example. Using techniques from queueing theory and occupancy problems, we use this model to analyze two parallel dynamic programming algorithms. We show that this model is simple to analyze and correctly predicts which algorithm will perform better in practice. The algorithms we consider are a pipeline algorithm, where each processor i computes in order the entries of rows i, i+p, and so on, where p is the number of processors; and a diagonal algorithm, where entries along each diagonal extending from the left to the top of the table are computed in turn. It is likely that the techniques used here can be useful in the analysis of other algorithms that use barriers or pipelining techniques