Korean Ocean Research and Development Institute

About: Korean Ocean Research and Development Institute is a facility organization based out in Busan, South Korea. It is known for research contribution in the topics: Sea surface temperature & Gene. The organization has 1770 authors who have published 3032 publications receiving 50142 citations.

Spirulina maxima Extract Ameliorates Learning and Memory Impairments via Inhibiting GSK-3β Phosphorylation Induced by Intracerebroventricular Injection of Amyloid-β 1-42 in Mice.

Abstract: Spirulina maxima, a microalga containing high levels of protein and many polyphenols, including chlorophyll a and C-phycocyanin, has antioxidant and anti-inflammatory therapeutic effects. However, the mechanisms where by Spirulina maxima ameliorates cognitive disorders induced by amyloid-β 1–42 (Aβ1–42) are not fully understood. In this study, we investigated whether a 70% ethanol extract of Spirulina maxima (SM70EE) ameliorated cognitive impairments induced by an intracerebroventricular injection of Aβ1–42 in mice. SM70EE increased the step-through latency time in the passive avoidance test and decreased the escape latency time in the Morris water maze test in Aβ1–42-injected mice. SM70EE reduced hippocampal Aβ1–42 levels and inhibited amyloid precursor protein processing-associated factors in Aβ1–42-injected mice. Additionally, acetylcholinesterase activity was suppressed by SM70EE in Aβ1–42-injected mice. Hippocampal glutathione levels were examined to determine the effects of SM70EE on oxidative stress in Aβ1–42-injected mice. SM70EE increased the levels of glutathione and its associated factors that were reduced in Aβ1–42-injected mice. SM70EE also promoted activation of the brain-derived neurotrophic factor/phosphatidylinositol-3 kinase/serine/threonine protein kinase signaling pathway and inhibited glycogen synthase kinase-3β phosphorylation. These findings suggested that SM70EE ameliorated Aβ1–42-induced cognitive impairments by inhibiting the increased phosphorylation of glycogen synthase kinase-3β caused by intracerebroventricular injection of Aβ1–42 in mice.

Evidence of minimal carbon sequestration in the productive Amundsen Sea polynya

Abstract: The Amundsen Sea polynya (ASP) is reportedly the most productive among the coastal polynyas around Antarctica. However, observational constraints limit our understanding of the biological pump and carbon cycle in the ASP. We measured various carbon-related parameters such as primary production, bacterial production, sinking flux of particulate organic carbon (POC), and accumulation of organic carbon in the sediment as well as hydrographic parameters during field observations and by instrument moorings. Over 95% of the photosynthetically produced POC was converted to suspended POC and/or dissolved carbon forms in the upper ~400 m layer. We postulate that most of the carbon transported to the water column by the biological pump in the ASP was flushed out of the shelf without being sequestered for long-term storage in sediments. Lack of bottom water formation due to intrusion of Circumpolar Deep Water in the lower layer reduces carbon sequestration efficiency.

Study on Control System of Integrated Unmanned Surface Vehicle and Underwater Vehicle

Abstract: In this paper, in order to overcome certain limitations of previously commercialized platforms, a new integrated unmanned surface vehicle (USV) and unmanned underwater vehicle (UUV) platform connected via underwater cable capable of acquiring real-time underwater data and long-time operation are studied. A catamaran-type USV was designed to overcome the limitations of an ocean environment and to play the role as the hub of power supply and communication for the integrated platform. Meanwhile, the UUV was designed as torpedo-shaped to minimize hydrodynamic resistance and its hardware design was focused on processing and sending the underwater camera and sonar data. The underwater cable driven by a winch system was installed to supply power from the USV to the UUV and to transmit acquired data form underwater sonar sensor or camera. Different from other previously studied cooperation system of USVs and autonomous underwater vehicles (AUVs), the merit of the proposed system is real-time motion coordination control between the USV and UUV while transmitting large amount of data using the tether cable. The main focus of the study is coordination of the UUV with respect to the global positioning system (GPS) attached at USV and verification of its performance throughout field tests. Waypoint tracking control algorithm was designed and implemented on USV and relative heading, distance control for USV-UUV coordination was implemented to UUV. To ensure the integrity of the coordination control of the integrated platform, a study on accurate measurement system of the relative position between the USV and the UUV by using the GPS and the ultrashort baseline (USBL) device was performed. Individual tests were conducted to verify the performance of USBL and AHRS, which provide the position and heading data of UUV among the sensors mounted on the actual platform, and the effectiveness of the obtained sensor data is presented. Using the accurate measurement system, a number of field tests were conducted to verify the performance of the integrated platform.

Tidal modification and its effect on sluice-gate outflow after completion of the Saemangeum dike, South Korea

Abstract: This study examined tidal modification and change in tidal currents caused by the construction of the Saemangeum dike, based on field observations and a numerical model. The Saemangeum dike was completed in April 2006, enclosing an estuarine area along the mid-western coast of South Korea. After closure of the dike, the tidal range outside the dike decreased slightly but significantly, while the inside tidal range decreased drastically. The numerical model results show that the dike construction has influenced tidal energy propagation and the tidal system in the Yellow Sea. The tidal current speed near the dike decreased abruptly following closure of the dike, except in front of the sluice gates. Since completion of the dike, outflow water discharged from the sluice gates has longer residence times due to the weakened tidal current; the change in the tidal current field has also caused greater northward expansion of outflow water. The sluice gates release fresher water, which spreads over the sea surface mainly by inertial momentum near the gate; this water is then gradually mixed with sea water farther from the gate. The less saline, possibly more contaminated outflow impacts the marine environment near the Saemangeum dike. Controlling the discharge and gate-opening timing can partially mitigate these impacts on the marine environment.