• Molecules and Cells
• /
• v.26 no.6
• /
• pp.590-594
• /
• 2008

brc-2, an ortholog of BRCA2 in Caenorhabditis elegans, is essential in the maintenance of genetic integrity. In C. elegans, cellular location correlates with meiotic progression, and transgene-induced cosuppression is observed in the germ line but not in somatic cells. We used these unique features to dissect the role of brc-2 in the germ line from that in somatic cells. In situ hybridization of wild type animals revealed that brc-2 gene expression was higher in oocytes than in other germline cells, and was barely detectable in mitotic cells. In contrast, germ cells containing multicopies of the brc-2 transgene showed no significant in situ hybridization signal at any oogenesis stage, confirming that brc-2 expression was functionally cosuppressed in the transgenic germ line. RAD-51 foci formation in response to DNA damage was abrogated in brc-2-cosuppressed germ cells, whereas wild-type germ cells showed strong RAD-51 foci formation. These germ cells exhibited massive chromosome fragmentation and decompaction instead of six bivalent chromosomes in diakinesis. Accordingly, lethality was observed after the early stage of germline development. These results suggest that brc-2 plays essential roles in chromosome integrity in early prophase, and therefore is crucial in meiotic progression and embryonic survival.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.14 no.5
• /
• pp.84-92
• /
• 2006

Freeway Corridors consist of urban freeways and parallel arterials that drivers can use alternatively. Ramp metering in freeways and signal control in arterials are contemporary traffic control methods that have been developed and applied in order to improve traffic conditions of freeway corridors. However, most of the existing studies have focused on either optimal ramp metering in freeways, or progression signal strategies between arterial intersections. There have been no traffic control systems in Korea that integrates the freeway ramp metering and arterial signal control. The effective control strategies for freeway operations may cause negative effects on arterial traffic. On the other hand, traffic congestion and bottleneck phenomenon of arterials due to the increasing peak-hour travel demand and ineffective signal operation may generate an accessibility problem to freeway ramps. Thus, the main function of the freeway which is the through-traffic process has not been successful. The purpose of this study is to develop an integrated control model that connects freeway ramp metering systems and signal control systems in arterial intersections. And Optimization of integrated control model which consists of ramp metering and signal control is another purpose. Optimization results are verified by comparison with the results from MATDYMO.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.15 no.1
• /
• pp.8-15
• /
• 2007

Freeway corridors consist of urban freeways and parallel arterials that drivers can use alternatively. Ramp metering in freeways and signal control in arterials are contemporary traffic control methods that have been developed and applied in order to improve traffic conditions of freeway corridors. However, most of the existing studies have focused on either optimal ramp metering in freeways, or progression signal strategies between arterial intersections. There have been no traffic control systems in Korea that integrates the freeway ramp metering and arterial signal control. The effective control strategies for freeway operations may cause negative effects on arterial traffic. On the other hand, traffic congestion and bottleneck phenomenon of arterials due to the increasing peak-hour travel demand and ineffective signal operation may generate an accessibility problem to freeway ramps. Thus, the main function of the freeway which is the through-traffic process has not been successful. The purpose of this study is to develop an integrated control model that connects freeway ramp metering systems and signal control systems in arterial intersections. And Optimization of integrated control model which consists of ramp metering and signal control is another purpose. The design of experiment, neural network, and simulated annealing are used for optimization.

• Molecular & Cellular Toxicology
• /
• v.1 no.1
• /
• pp.62-71
• /
• 2005

For toxicity model in the kidney, renal cell carcinoma (RCC) is one of the most important model to assess the structural and functional alterations. Most RCCs are sporadic, and environmental agents are suspected to play a role in the etiology of the disease. In this study, we discovered novel evidence for previously unknown gene expression patterns related to progression according to cancer stage in RCC. Four clear cell RCC tissue samples along with five corresponding patient-matched normal kidney tissue samples were obtained from patients undergoing partial or radical nephrectomy. To examine the difference of gene expression profile in clear cell RCC, radioactive cDNA microarrays were used to evaluate changes in the expression of 1,152 genes in a total. Using $^{33}P-labeled$ probes, this method provided highly sensitive gene expression profiles including drug metabolism, and cellular signaling. 29 genes were identified with expression levels that differed by more than 2.0 value of z-ratio, compared with that in control. Whereas expression of 38 genes were decreased by less than-2.0 value of z-ratio. In conclusion, this study has identified 67 gene expression alterations in clear-cell type of RCC. Most notably, genes involved in cell growth were up-regulated in stage I more than stage III whereas genes involved in signal transduction were down-regulated in which both stage I and stage III. The identified alteraions of gene expression will likely give in sight in to clear cell RCC and tumor progression.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.1
• /
• pp.245-252
• /
• 2014

Human METCAM/MUC18, a cell adhesion molecule (CAM) in the immunoglobulin-like gene super family, plays a dual role in the progression of several epithelium cancers; however, its role in the nasopharyngeal carcinoma (NPC) remains unclear. To initiate the study we determined human METCAM/MUC18 expression in tissue samples of normal nasopharynx (NP), NPCs, and metastatic lesions, and in two established NPC cell lines. Immunoblotting analysis was used for the determination in lysates of frozen tissues, and immunohistochemistry (IHC) for expression in formalin-fixed, paraffin-embedded tissue sections of 7 normal nasopharynx specimens, 94 NPC tissue specimens, and 3 metastatic lesions. Human METCAM/MUC18 was expressed in 100% of the normal NP, not expressed in 73% of NPC specimens (or expressed at very low levels in only about 27% of NPC specimens), and expressed again in all of the metastatic lesions. The level of human METCAM/MUC18 expression in NPC tissues was about one fifth of that in the normal NP and metastatic lesions. The low level of human METCAM/MUC18 expression in NPC specimens was confirmed by a weak signal of RT-PCR amplification of the mRNA. Low expression levels of human METCAM/MUC18 in NPC tissues were also reflected in the seven established NPC cell lines. These findings provided the first evidence that diminished expression of human METCAM/MUC18 is an indicator for the emergence of NPC, but increased expression then occurs with metastatic progression, suggesting that huMETCAM/MUC18, perhaps similar to TGF-${\beta}$, may be a tumor suppressor, but a metastasis promoter for NPC.

• Journal of Korean Neurosurgical Society
• /
• v.40 no.5
• /
• pp.351-356
• /
• 2006

Objective : Spondylodiscitis has been diagnosed by clinical, radiological and laboratory methods. MR imaging is well known as an excellent diagnostic tool for spondylodiscitis. However, the changes in MR images throughout the treatment process has not been studied. Thus we have analyzed the serial changes of MR images throughout the stages of infection. Methods : Ten patients were selected for retrospective reviewed who had been treated at our institute for infectious spondylodiscitis between 2000 and 2005. These patients had been followed-up at least six months and had taken more than a couple of series of MR scans. We classified the MR images into four groups according to the stages of treatment for the infection and compared them to the clinical and laboratory findings. Results : MR image signals changed minimally or appeared to be normal in the early stages. The progression of spondylodiscitis was characterized by a low T1 WI signal and a high T2 WI signal in disc and vertebral body. The signal changes of the MR images were then propagated and the end plate was destructed. During the treatment, the destructed endplate became stabilized and the signal intensity of both T1 and T2 WI were fixed to low-or iso-intensity. Conclusion : We can determine the serial signal changes based on MR images according to the treatment of spondylodiscitis. We can therefore determine the status of the infection and the stage of treatment, as well as the diagnosis of spondylodiscitis using serial MR images.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.11 no.1
• /
• pp.1-12
• /
• 2012

Even though the semi-actuated signal control system based on image detectors has been spreading in Korea, any appropriate methods to evaluate the effectiveness and performance has not been established yet. Therefore, this research effort is aiming at developing a systematic method for evaluating the effectiveness and performance of the semi-actuated signal control system based on image detectors. To this end, this research firstly established measures of effectiveness(MOEs) and associated information to be surveyed from fields. Secondly, this research provided a procedure and methodology to evaluate any improvements due to the introduction of a semi-actuated signal control system based on image detectors. The developed methodology was examined at a case study site located in the city of Paju. As a result of the evaluation, the MOEs including traffic throughput, travel speeds, split usage rate, progression rate, etc. showed positive improvements though individual signalized intersections as well as coordinated corridors.

• Journal of Korean Society of Transportation
• /
• v.24 no.7 s.93
• /
• pp.101-114
• /
• 2006

Recently due to the increase of cars and city life, the traffic congestion has worsened. It Is particularly worse in the center of the metropolis. Within the general public means, the public transport buses have the advantage of being more cheap, accessible and mobile. But as there is no separate lane for buses, the collision of cars and buses are creating damage to public service. In order to solve this situation, the bus priority signal system has been introduced to reduce the bus travel time and improve its services. The purpose of this study is to establish bus priority signal algorithm which builds bus efficiency under the real-time traffic signal control system and to analyze the effect of it. As the green time was calculated against real time (under the real-time traffic signal control system), compared to existing bus priority signal there was a reduction in cross street loss. The modified cycle was used to maintain signal progression. A case study was carried out using VISSIM simulation model. In result of this study, we found that there was a decrease in bus travel time despite some evidence of car delays and compared to existing bus priority signal the delay of dishonor could be reduced dramatically. The analysed result of person delay using MOE, is that there is evidence that when bus priority signal is in effect, the person delay is reduced.

• Journal of Korean Society of Transportation
• /
• v.27 no.5
• /
• pp.17-28
• /
• 2009

There are many limitations in dealing with rapidly changing traffic demand in urban cities. Thus recently, traffic operation and management skills are more emphasized rather than the expansion of traffic facilities. In particular, in the interrupted flow formed by signalized intersections, it is quite important to give optimal signal timing to each intersection with consideration of progression. However, as fixed signal times per direction can affect passing capacity in signalized intersections, the present four-signal phase including a left-turn signal has many limitations, including reduction of directional road capacity when traffic demand is increases dramatically during peak hours. Because of this problem, lots of studies about internal metering techniques for oversaturated signal control skills have progressed but these techniques are not used widely due to the absence of detectors for queue sensing in real-time signal control systems. In this research, a new methodology called the "restrictive left-turn signal control", which is already used at the intersection above Samsung subway station, is suggested in order to reduce control delay of urban arterial roads. The restrictive left-turn signal control allows a driver to make a U-turn and then a right turn instead of turning left in that intersection. With this change, the restrictive left-turn signal control can contribute to increased intersection capacity by reducing the number of signal phases and maximizing the through phase time. However, road structure and traffic conditions at the target intersections should be considered before the adoption of the proposed signal control.

• Journal of Korean Society of Transportation
• /
• v.33 no.1
• /
• pp.70-80
• /
• 2015

In recent years, tram has been the focus of a new mode of public transportation that can solve traffic jams and decrease public transit usage and environmental problem. This research is in the works to develop a tram signal controller and signal control strategies, and aim to resolve the problem of what could happen if a tram system was installed in general road. We developed the hierarchical signal control strategies to obtain a minimum tram bandwidth and to minimize vehicle delay, in order to perform a priority control to include passive and active signal priority control strategies. The strategies was produced for S/W and H/W, it is based in standard traffic signal controller. We conducted a micro simulation test to evaluate the hierarchical signal control strategies, which showed that the developed optimization model is effective to prevent a tram's stop in intersection, to reduce a tram's travel time and vehicle's delay.