High power narrow linewidth discrete mode laser diode integrated with a curved semiconductor optical amplifier emitting at 2051 nm.

We report on a 2.051 µm InxGaAs/InP-based discrete mode laser diode monolithically integrated with a curved tapered semiconductor optical amplifier for CO2 sensing applications. At a heat-sink temperature of 0°C, the laser emits a record InP value of more than 35 mW continuous-wave output power in a single longitudinal mode.

A pilot project in distance education: nurse practitioner students' experience of personal video capture technology as an assessment method of clinical skills.

This paper reports on a pilot project aimed at exploring postgraduate distance students' experiences using personal video capture technology to complete competency assessments in physical examination. A pre-intervention survey gathered demographic data from nurse practitioner students (n=31) and measured their information communication technology fluency. Subsequently, thirteen (13) students were allocated a hand held video camera to use in their clinical setting. Those participating in the trial completed a post-intervention survey and further data were gathered using semi-structured interviews. Data were analysed by descriptive statistics and deductive content analysis, and the Unified Theory of Acceptance and Use of Technology (Venkatesh et al., 2003) were used to guide the project. Uptake of the intervention was high (93%) as students recognised the potential benefit. Students were video recorded while performing physical examinations. They described high level of stress and some anxiety, which decreased rapidly while assessment was underway. Barriers experienced were in the areas of facilitating conditions (technical character e.g. upload of files) and social influence (e.g. local ethical approval). Students valued the opportunity to reflect on their recorded performance with their clinical mentors and by themselves. This project highlights the demands and difficulties of introducing technology to support work-based learning.

Monitoring microbial community structure and dynamics during in situ U(VI) bioremediation with a field-portable microarray analysis system.

The objective of this study was to develop and validate a simple, field-portable, microarray system for monitoring microbial community structure and dynamics in groundwater and subsurface environments, using samples representing site status before acetate injection, during Fe-reduction, in the transition from Fe- to SO(4)(2-)-reduction, and into the SO(4)(2-)-reduction phase. Limits of detection for the array are approximately 10(2)-10(3) cell equivalents of DNA per reaction. Sample-to-answer results for the field deployment were obtained in 4 h. Retrospective analysis of 50 samples showed the expected progression of microbial signatures from Fe- to SO(4)(2-) -reducers with changes in acetate amendment and in situ field conditions. The microarray response for Geobacter was highly correlated with qPCR for the same target gene (R(2) = 0.84). Microarray results were in concordance with quantitative PCR data, aqueous chemistry, site lithology, and the expected microbial community response, indicating that the field-portable microarray is an accurate indicator of microbial presence and response to in situ remediation of a uranium-contaminated site.

Geophysical monitoring of hydrological and biogeochemical transformations associated with Cr(VI) bioremediation.

Understanding how hydrological and biogeochemical properties change over space and time in response to remedial treatments is hindered by our ability to monitor these processes with sufficient resolution and over field relevant scales. Here, we explored the use of geophysical approaches for monitoring the spatiotemporal distribution of hydrological and biogeochemical transformations associated with a Cr(VI) bioremediation experiment performed at Hanford, WA. We first integrated hydrological wellbore and geophysical tomographic data sets to estimate hydrological zonation at the study site. Using results from laboratory biogeophysical experiments and constraints provided by field geochemical data sets, we then interpreted time-lapse seismic and radar tomographic data sets, collected during thirteen acquisition campaigns over a three year experimental period, in terms of hydrological and biogeochemical transformations. The geophysical monitoring data sets were used to infer: the spatial distribution of injected electron donor; the evolution of gas bubbles; variations in total dissolved solids (nitrate and sulfate) as a function of pumping activity; the formation of precipitates and dissolution of calcites; and concomitant changes in porosity. Although qualitative in nature, the integrated interpretation illustrates how geophysical techniques have the potential to provide a wealth of information about coupled hydrobiogeochemical responses to remedial treatments in high spatial resolution and in a minimally invasive manner. Particularly novel aspects of our study include the use of multiple lines of evidence to constrain the interpretation of a long-term, field-scale geophysical monitoring data set and the interpretation of the transformations as a function of hydrological heterogeneity and pumping activity.