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Phosphorous concentrations exceed water quality guidelines in most of the major rivers in southern Quebec. The problem is particularly acute in the Pike River, which drains into the Missisquoi Bay of Lake Champlain, in southeastern Quebec. Elevated phosphorus concentrations can lead to a reduction in the palatability of drinking water, a decrease in diversity of aquatic life and loss of recreational opportunities. All of these problems have been observed in the Bay. / Two agricultural fields (the Marchand and Gagnon sites) located on the Pike River watershed, in southeastern Quebec were selected and equipped with instrumentation to measure and evaluate the partitioning of phosphorus between surface runoff and subsurface drainage, on a year round basis. The snowmelt event was the dominant surface and subsurface event for the 2000/2001 hydrological year. On the Marchand site surface flow data was incomplete as a result of a failure of the surface runoff flume. On both sites the IF 200 subsurface flow meters failed, which resulted in missing subsurface flow data during certain runoff events. Therefore, the majority of the comparisons made relate to the Gagnon site. / The 2000/2001 hydrological year was unusually dry, which resulted in a limited number of surface and subsurface runoff events. The annual depth of surface runoff for the Gagnon site was 87.5 mm/ha, of which only 0.2mm occurred outside the snowmelt event. The estimated depth of subsurface runoff of the snowmelt event at the Gagnon site based upon a water balance equation was 93.7 mm/ha, or 51.7% of the total volume that occurred on the Gagnon field during the snowmelt event. / The total phosphorus load in surface runoff for the spring snowmelt at the Gagnon site was 166.4 g/ha, whereas the estimated total phosphorus load in subsurface drainage was 98.2 g/ha, or 37.1% of the total load. Subsurface drains can therefore be a significant pathway for phosphorus losses.

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Eye tracking research is a growing area and the fields as where eye trackingcould be used in research are large. To understand the eye tracking data dif-ferent filters are used to classify the measured eye movements. To get accu-rate classification this thesis has investigated the possibility to measure bothhead movements and eye movements in order to improve the estimated gazepoint.The thesis investigates the difference in using head movement compensationwith a velocity based filter, I-VT filter, to using the same filter without headmovement compensation. Further on different velocity thresholds are testedto find where the performance of the filter is the best. The study is made with amobile eye tracker, where this problem exist since you have no absolute frameof reference as opposed to when using remote eye trackers. The head move-ment compensation shows promising results with higher precision overall.

A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / Children with prolonged mechanical ventilation after cardiac surgery have a higher risk for poor outcome due to a variety of ventilator‐associated morbidities. It therefore becomes essential to identify these children at higher risk of prolonged mechanical ventilation as well as find methods to identify children ready to be extubated as early as possible to avoid these complications. One physiological variable, the pulmonary dead space fraction (VD/VT), has been suggested as a possible indicator of prolonged mechanical ventilation. VD/VT essentially measures the amount of ventilated air that is unable to participate in gas exchange. Can VD/VT be used successfully in children undergoing cardiac surgery to identify those at risk for prolonged mechanical ventilation and identify those ready for extubation? Retrospective chart review of 461 patients at Phoenix Children’s Hospital in the Pediatric Cardiac Intensive Care Unit since the initiation of standard application of the Philips NM3 monitors in October 2013 through December 2014. From the 461 patients screened, only 99 patients met all the inclusion criteria. These 99 patients consisted of 29 patients with balanced single ventricle physiology and 61 patients with two ventricle physiology. Initial postoperative and pre‐extubation VD/VT values correlated with length of mechanical ventilation for patients with two ventricle physiology but not for patients with single ventricle physiology. Additionally, pre‐extubation VD/VT values of greater than 0.5 indicated higher rates of extubation failure in two ventricle patients. Conclusion: For children with two ventricle physiology undergoing cardiac surgery, VD/VT should be used clinically to estimate the length of mechanical ventilation for these children. VD/VT should also be checked in these patients before attempting to extubate. If VD/VT is found to be higher than 0.5, extubation should not be attempted since the patient is at a much higher risk for extubation failure.

Thesis (D. Min.)--Trinity Evangelical Divinity School, 2002. / Abstract. Includes bibliographical references (leaves 394-401).

A study was conducted to assess the efficiency of a constructed wetland for sediment and nutrient removal from a riverine source containing non-point source pollution (NPS) in a Nordic climate. The constructed wetland, built near the town of Mystic, Southern Quebec, consists of a sedimentation basin, a sinuous subsurface horizontal flow section and an open water body or pond that continuously receives up to 5% of Walbridge Creek. Flow into and through the system is controlled by gravity. There is a gate on the intake structure, which allows inflow into the wetland to be adjusted, along with three composite weirs; located at the outlet of each section of the wetland. Water samples were analyzed for orthophosphates (PO4), dissolved phosphorus (DP), total phosphorus (TP), ammonium (NH4+) and nitrates (NO3-) The study occurred from May to December 2003 and from May to December 2004. In 2003, there was a 33.6% reduction in TP load from intake to outlet with a retention rate of 2.23 g m-2 year-1. The greatest reduction in TP load during 2003 took place during the summer months (32.2%). In 2004, there was a further reduction of 42.8% in TP load from intake to outlet with a retention rate of 1.56 g m-2 year-1 compared to 2003. The largest reduction in TP load during the operational year of 2004 took place during the summer months (43.7%). Within the wetland, both the submerged flow section and open water basin showed similar and significant reductions of TP load in 2003 and 2004 annually and seasonally. Both annually and seasonally in 2003, NO3- showed no significant decrease in load from intake to outlet or within portions of the wetland. In 2004, there was a 22% annual load reduction from intake to outlet with a retention rate of 43.9 g m-2 year-1. The largest reduction in NO3- load during 2004 took place during the summer months (25.6%). Within the wetland, the submerged flow section showed the greatest reduction in NO3- concentrations annually and during the summer months of 2004. These results confirm the range of treatment efficiencies that can be achieved using a constructed wetland for NPS pollution in a Nordic climate.

Two tile-drained agricultural fields in the Pike River watershed of Southern Quebec were instrumented in October 2000 to monitor phosphorus and nitrate concentrations in surface runoff and tile drainage. Data collected from these sites were used as the primary input to test a GIS-based hydrological and water quality simulation model (ArcView SWAT2000) at the field scale. Surface runoff, subsurface flow, sediment yield, nitrate loads and phosphorus loads were the principal parameters evaluated by the model. The SWAT model was calibrated using data collected in the year 2002 while 2003 data was used for validating the model. Particulate phosphorus and total dissolved phosphorus loads in streamflow were also simulated using SWAT and compared with field measurements. / A sensitivity analysis showed that curve number, available soil water content and soil evaporation factors significantly influenced water yield simulations while model performance for water quality parameters was governed mainly by the accuracy of simulating field operations such as fertilization and tillage. The monthly coefficients of performance after calibration ranged from being very good for some parameters (0.27 to 0.66 for total water yield; 0.38 to 0.67 for total phosphorus; and 0.23 to 0.89 for sediments) to being inconsistent for others (0.44 to 2.28 for subsurface flow; 0.63 to 4.36 for surface runoff; and 0.66 to 1.35 for total nitrate loads). Overall, it was found that SWAT results on a seasonal scale were generally more reliable whereas daily or monthly simulations could be improved by using a longer calibration period or incorporating model changes. Short-term impacts of implementing different best management practices for tillage, crop rotation and fertilization were also evaluated using the validated SWAT model. It was found that conservation tillage of corn coupled with pasture or soybean rotations can reduce total phosphorus loads in the range of 25-50% over conventional tillage with corn.