Macrotidal beach monitoring (Belgium) using hypertemporal terrestrial lidar

Macrotidal Beach Monitoring (Belgium) using Hypertemporal Terrestrial Lidar Greet DERUYTER, Lars De SLOOVER, Jeffrey VERBEURGT, Alain DE WULF, Belgium and Sander VOS, the NetherlandsKey words: Continuous Terrestrial Laser Scanning, Coastal Monitoring, Beach Mapping, North SeaSUMMARY In order to protect the Belgian coast, knowledge on natural sand dynamics is essential. Monitoring sand dynamics is commonly done through sediment budget analysis, which relies on determining the volumes of sediment added or removed from the coastal system. These volumetrics require precise and accurate 3D data of the terrain on different time stamps. Earlier research states the potential of permanent long-range terrestrial laser scanning for continuous monitoring of coastal dynamics. For this paper, this methodology wasimplemented at an ultradissipative macrotidal North Sea beach in Mariakerke (Ostend, Belgium). A Riegl VZ-2000 LiDAR, mounted on a 42 m high building, scanned the intertidal and dry beach in a test zone of ca. 200 m wide on an hourly basis over a time period of one year.It appeared that the laser scanner could notbe assumed to have a fixed zenith for each hourly scan. The scanner compensator measured a variable deviation of the Z-axis of more than 3.00 mrad. This resultedin a deviation of ca. 900 mm near the low water line. A robust calibration procedure was developed to correct the deviations of the Z-axis. In this paper, we start by presenting the first results achieved with the current methodology. Next, we analyze the results from a 10-day measurement campaignand highlight the tide-dominated beach morphology

Macrotidal beach monitoring (Belgium) using hypertemporal terrestrial lidar

Macrotidal Beach Monitoring (Belgium) using Hypertemporal Terrestrial Lidar Greet DERUYTER, Lars De SLOOVER, Jeffrey VERBEURGT, Alain DE WULF, Belgium and Sander VOS, the NetherlandsKey words: Continuous Terrestrial Laser Scanning, Coastal Monitoring, Beach Mapping, North SeaSUMMARY In order to protect the Belgian coast, knowledge on natural sand dynamics is essential. Monitoring sand dynamics is commonly done through sediment budget analysis, which relies on determining the volumes of sediment added or removed from the coastal system. These volumetrics require precise and accurate 3D data of the terrain on different time stamps. Earlier research states the potential of permanent long-range terrestrial laser scanning for continuous monitoring of coastal dynamics. For this paper, this methodology wasimplemented at an ultradissipative macrotidal North Sea beach in Mariakerke (Ostend, Belgium). A Riegl VZ-2000 LiDAR, mounted on a 42 m high building, scanned the intertidal and dry beach in a test zone of ca. 200 m wide on an hourly basis over a time period of one year.It appeared that the laser scanner could notbe assumed to have a fixed zenith for each hourly scan. The scanner compensator measured a variable deviation of the Z-axis of more than 3.00 mrad. This resultedin a deviation of ca. 900 mm near the low water line. A robust calibration procedure was developed to correct the deviations of the Z-axis. In this paper, we start by presenting the first results achieved with the current methodology. Next, we analyze the results from a 10-day measurement campaignand highlight the tide-dominated beach morphology

Single-use duodenoscopes compared with reusable duodenoscopes in patients carrying multidrug-resistant microorganisms:a break-even cost analysis

Background and study aims:Single-use duodenoscopescan prevent transmission of microorganisms through contaminated reusable duodenoscopes. Concerns regardingtheir economic and environmental impact impede the transition to single-use duodenoscopes. This study investigatedthe costs associated with two scenarios in which single-useduodenoscopes are used in patients carrying multidrug-resistant microorganisms (MDROs).Methods:Break-even costs for single-use duodenoscopeswere calculated for two scenarios in which patients werescreened for MDRO carriage before undergoing endoscopicretrograde cholangiopancreatography (ERCP). Only directcosts related to the endoscopy were taken into consideration. In Scenario 1, patients were screened through microbiological culturing with a lag time in receiving the test result. In Scenario 2, screening was performed using GeneXpert analysis providing a rapid read-out. Calculations wereperformed using data from a Dutch tertiary care centerand also with US healthcare data.Results:In the Dutch situation, single-use duodenoscopesneeded to be priced at a maximum of € 140 to € 250 tobreak-even. In the US analyses, break-even costs variedwidely, depending on the duodenoscope-associated infection costs used, ERCP volume, and infection risk. Thebreak-even costs in Scenario 1 ranged between $78.21 and$2,747.54 and in Scenario 2, between $248.89 and$2,209.23.Conclusions:This study showed that a crossover scenarioin which single-use duodenoscopes are only used in patients carrying MDROs could be an economically viable alternative to a complete transition to single-use duodenoscopes. In the Dutch setting, single-use duodenoscopesneed to be priced much lower than in the United States toreach a per-procedure cost that is comparable with a scenario using reusable duodenoscopes exclusively