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Accurately measuring the dissolved oxygen concentration in the ocean has been the subject of considerable research. Traditionally, the calibration and correction of profiling oxygen measurements has centered on static, steady-state errors, leaving dynamic or time-dependent errors in the sensor response largely untreated. This study evaluates a reengineered Sea-Bird Electronics dissolved-oxygen Clark electrode (SBE 43) and demonstrates the characterization of sensor time response over oceanographic temperatures and pressures as well as treating a time-dependent, pressure-induced effect observed as hysteresis, most notably in deep-ocean oxygen profiles. The effects of temperature and pressure on sensor response are measured separately and then combined into an expression for evaluating an in situ time constant. The physics of the pressure-induced hysteresis in oxygen sensors are discussed and modeled for many individual sensors in several locations throughout the world's oceans. This effort reduces the underlying uncertainty of Clark oxygen sensors to approximately 0.1% of the measured signal, which is equivalent to the accuracy of the chemical calibration standard.

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Abstract:The Community Engagement Model was developed as a tool for the production of health communication videos for broadcast on local television stations. The model, a hybrid of participatory video design and social marketing techniques, uses iterative design principles for both production and evaluation. This article reports on the use of this model for the design and production of a series of videos aimed at promoting awareness of the BC NurseLine (a 24-hour telephone health service) among Farsi speakers in the Greater Vancouver area. Statistical analysis of project-related data suggests that the use of an extensive, culturally engaged process to produce and evaluate the videos was integral to its success. The steps taken in this campaign are described to show how the Community Engagement Model can be used to produce effective, culturally sensitive, participatory media targeted at specific communities. Keywords Canadian Journal of Communication, Vol 32 (2007) 383-400©2007 Canadian Journal of Communication Corporation des principes de design itératif pour la production ainsi que l'évaluation. Le présent document décrit l'utilisation de ce modèle dans la conception et la production d'une série de vidéos ayant pour but de mieux faire connaître le BC NurseLine (service d'info-santé 24-h de la Colombie Britannique) auprès de la communauté farsi dans la région métropolitaine de Vancouver. Une analyse statistique suggère que l'intégration d'un processus extensif et engagé au niveau culturel, tant dans la production que dans l'évaluation de ces vidéos, a été un facteur clé dans leur succès. Le processus suivi lors de cette campagne est décrit pour montrer comment le modèle d'engagement communautaire puisse être employé pour produire des médias participatifs, à la fois efficaces et adaptés aux spécificités culturelles, ciblant des communautés spécifiques.

We describe a collaborative effort to develop and implement a new integrated water quality monitoring package that provides continuous and simultaneous multi-parameter physical and biogeochemical measurements, including: conductivity, temperature, pressure, dissolved oxygen, chlorophyll fluorescence, and turbidity. The "Water Quality Monitor" (WQM) features autonomous operation and multiple anti-fouling approaches, and is intended for long-term deployments (months) in potentially high-fouling coastal environments. Our primary objectives for our in-field tests are 1) to collect high quality data for > 3 months without the need for instrument service, 2) to present results from field trials in coastal regimes in order to assess the WQM's longevity and efficacy of multiple antifoulant approaches, and 3) to demonstrate that the WQM as a single, multi-sensor instrument provides reliable, multiparameter data in a single data stream, simplifying data analysis and management for ocean observing system integrators. Results from preliminary performance testing of the WQM deployed in Chesapeake Bay, MD, from April 20, 2006 to July 3, 2006 showed negative effects of biofouling within 2 months. Lessons learned from this deployment helped evolve the instrument design and highlighted the need for more aggressive measures to deter the effect of biofouling. To determine the best approach to further reduce the effect of biofouling over the deployment period in addition to copper guards, WQMs were deployed with Sea-Bird Anti-Foulant cartridges (AF) only, WET Labs BLeach Injection System (BLIS) only, or a combination of AF and BLIS. A total of 5 prototype WQMs were deployed in two separate coastal environments. Sea-Bird Electronics conducted tests at Shilshole Marina, WA continuously for 5 months straddling the end of the summer growing season, fall and winter months (August 15, 2006 to January 15, 2007. WET Labs conducted tests in Yaquina Bay, OR for just over 4 months during similar growth conditions (September 13, 2006 to January 23, 2007. Since the deployment period extended from late summer to winter, biofouling conditions were considered to be moderate. Results show temperature, salinity, dissolved oxygen, turbidity and chlorophyll fluorescence values were highly coherent among multiple instruments over 4 and 5 month deployment durations. WQMs equipped with either the AF or combination of AF + BLIS recorded high quality data for 110 -152 days (> 3-5 months). Of particular importance was the stability of the dissolved oxygen measurements which showed less than 5% signal degradation over the deployment period. In-field validation measurements of dissolved oxygen were made with a calibrated reference SBE43 dissolved oxygen sensor and with discrete water samples for Winkler analysis. Temperature and salinity were very stable based on pre and post-deployment calibrations and drift was < 0.001 degrees C and 0.006 psu, respectively. Designed specifically to address the ocean and estuarine observing needs, the WQM provides a reliable,...