• Title/Summary/Keyword: Causative factor

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Time to change from a simple linear model to a complex systems model

  • Hong, Yun-Chul
    • Environmental Analysis Health and Toxicology
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    • v.31
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    • pp.8.1-8.2
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    • 2016
  • A simple linear model to test the hypothesis based on one-on-one relationship has been used to find the causative factors of diseases. However, we now know that not just one, but many factors from different systems such as chemical exposure, genes, epigenetic changes, and proteins are involved in the pathogenesis of chronic diseases such as diabetes mellitus. So, with availability of modern technologies to understand the intricate nature of relations among complex systems, we need to move forward to the future by taking complex systems model.

Expression of Vascular Endothelial Growth Factor and Peritumoral Brain Edema in Intracranial Meningiomas (수막종에서 혈관내피성장인자의 발현과 종양주변부 부종)

  • Kim, Tae Young;Park, Jong Tae;Han, Weon Cheol;Moon, Seong Keun
    • Journal of Korean Neurosurgical Society
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    • v.29 no.9
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    • pp.1222-1227
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    • 2000
  • Objective : Vascular endothelial growth factor(VEGF), an endothelial cell specific cytokine, is a potent angiogenic growth factor implicated in the tumor angiogenesis and increases vascular permeability dramatically. Peritumoral brain edema(PTBE) occurs in 40-60% of meningiomas. Many causative factors have been investigated, but the mechanism of PTBE associate with meningioma is unclear. VEGF has been implicated as one of the causative factors of PTBE. This study was designed to determine whether the extent of VEGF expression is correlated with degree of PTBE in meningiomas. Methods : Meningioma tissue samples from 40 patients(7 men and 33 women, mean age $53{\pm}13years$) who underwent surgery were examined retrospectively for the expression of VEGF immunohistochemically. The extent of PTBE was estimated by using preoperative CT or MRI as an edema index(EI). In addition to VEGF, several causative factors including tumor size, location, histologic type, microvasculature(CD31) were compared with EI. Results : Twenty-six meningiomas demonstrated PTBE, and the other 14 did not. Of the 40 patients of meningiomas, 28 were positive(17 were 1+ and 11 were 2+) for VEGF. The EI increased significantly just as VEGF was strongly expressed(p=0.006). Microvascular proliferation was also closely correlated with the extent of peritumoral brain edema(p<0.05). Conclusion : These data suggest that VEGF expression and microvascular proliferation are closely correlated with PTBE in meningioma.

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Stochastic Strong Ground Motion Simulation at South Korean Metropolises' Seismic Stations Based on the 2016 Gyeongju Earthquake Causative Fault (2016년 경주지진 원인단층의 시나리오 지진에 의한 국내 광역도시 지진관측소에서의 추계학적 강진동 모사)

  • Choi, Hoseon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.25 no.6
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    • pp.233-240
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    • 2021
  • The stochastic method is applied to simulate strong ground motions at seismic stations of seven metropolises in South Korea, creating an earthquake scenario based on the causative fault of the 2016 Gyeongju earthquake. Input parameters are established according to what has been revealed so far for the causative fault of the Gyeongju earthquake, while the ratio of differences in response spectra between observed and simulated strong ground motions is assumed to be an adjustment factor. The calculations confirm the applicability and reproducibility of strong ground motion simulations based on the relatively small bias in response spectra between observed and simulated strong ground motions. Based on this result, strong ground motions by a scenario earthquake on the causative fault of the Gyeongju earthquake with moment magnitude 6.5 are simulated, assuming that the ratios of its fault length to width are 2:1, 3:1, and 4:1. The results are similar to those of the empirical Green's function method. Although actual site response factors of seismic stations should be supplemented later, the simulated strong ground motions can be used as input data for developing ground motion prediction equations and input data for calculating the design response spectra of major facilities in South Korea.

A Study on the Classification and Causative Factor of Vacant Houses - Focused on the Incheon Metropolitan City - (빈집발생의 유형과 발생에 영향을 미치는 요인에 관한 연구 - 인천광역시 사례를 중심으로 -)

  • Lim, Chang-Il;Na, In-Su
    • Journal of KIBIM
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    • v.10 no.1
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    • pp.23-29
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    • 2020
  • The vacant houses commonly observed in urban aging are considered to be representative signs of urban decline. Vacant houses are themselves vulnerable to security, and in particular, they are exposed to disasters due to poor management, which can accelerate the decline of the area. This study is to classify the area and analyze the causes and characteristics of the occurrence of vacant houses by type based on the data through the survey on the vacant houses in Incheon. This research analyze vacant house data survey so to characterized and categorized types of vacant houses. The criteria of vacant houses analysis are population density, population growth, aging extent. In conclusion there are four types of region in Incheon area according to housing types, hazard classes, building age and building areas. Type A is inner city, type B is mixed, type C is expandable and type D is unsular types.

Development of New NMDA Receptor Agonists/Antagonists

  • Park, No-Sang
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.72-74
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    • 2003
  • Excitatory amino acid (EAA) receptor, particularly NMDA receptor, are now known to be one of major transmitter receptors involved in synaptic excitation. Excessive release of EAA neurotransmitter, glutamate, is an important causative factor in the neurodegenerative processes and can cause neuronal damage and cell death. This excitotoxicity has been shown to be $Ca^{++}$ dependent. (omitted)

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Landslide susceptibility mapping using Logistic Regression and Fuzzy Set model at the Boeun Area, Korea (로지스틱 회귀분석과 퍼지 기법을 이용한 산사태 취약성 지도작성: 보은군을 대상으로)

  • Al-Mamun, Al-Mamun;JANG, Dong-Ho
    • Journal of The Geomorphological Association of Korea
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    • v.23 no.2
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    • pp.109-125
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    • 2016
  • This study aims to identify the landslide susceptible zones of Boeun area and provide reliable landslide susceptibility maps by applying different modeling methods. Aerial photographs and field survey on the Boeun area identified landslide inventory map that consists of 388 landslide locations. A total ofseven landslide causative factors (elevation, slope angle, slope aspect, geology, soil, forest and land-use) were extracted from the database and then converted into raster. Landslide causative factors were provided to investigate about the spatial relationship between each factor and landslide occurrence by using fuzzy set and logistic regression model. Fuzzy membership value and logistic regression coefficient were employed to determine each factor's rating for landslide susceptibility mapping. Then, the landslide susceptibility maps were compared and validated by cross validation technique. In the cross validation process, 50% of observed landslides were selected randomly by Excel and two success rate curves (SRC) were generated for each landslide susceptibility map. The result demonstrates the 84.34% and 83.29% accuracy ratio for logistic regression model and fuzzy set model respectively. It means that both models were very reliable and reasonable methods for landslide susceptibility analysis.

Preliminary strong ground motion simulation at seismic stations within nuclear power plant sites in South Korea by a scenario earthquake on the causative fault of 2016 Gyeongju earthquake

  • Choi, Hoseon
    • Nuclear Engineering and Technology
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    • v.54 no.7
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    • pp.2529-2539
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    • 2022
  • Stochastic and an empirical Green's function (EGF) methods are preliminarily applied to simulate strong ground motions (SGMs) at seismic stations within nuclear power plant (NPP) sites in South Korea by an assumed large earthquake with MW6.5 (scenario earthquake) on the causative fault of the 2016 Gyeongju earthquake with MW5.5 (mainshock). In the stochastic method, a ratio of spectral amplitudes of observed and simulated waveforms for the mainshock is assumed to be an adjustment factor. In the EGF method, SGMs by the mainshock are simulated assuming SGMs by the 2016 Gyeongju earthquake with MW5.0 (foreshock) as the EGF. To simulate SGMs by the scenario earthquake, a ratio of fault length to width is assumed to be 2:1 in the stochastic method, and SGMs by the mainshock are assumed to be EGF in the EGF method. The results are similar based on a bias of the simulated response spectra by the two methods, and the simulated response spectra by the two methods exceeded commonly standard design response spectra anchored at 0.3 g of NPP sites slightly at a frequency band above 4 Hz, but considerable attention to interpretation is required since it is an indirect comparison.

Analysis of Voter's Acceptance to Female Politician's Appearance

  • Kwon, Tae-Soon;Yang, Cheui-Kyung
    • Journal of Fashion Business
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    • v.8 no.6
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    • pp.103-112
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    • 2004
  • A Politician Appearance Acceptance Model (PAAM model) was formed and designed based on an analysis of how the electorate would accept a female politician. The PAAM model evaluated factors which influenced the voter's view of the female politician based on appearance. Causative factors were assessed that impacted acceptance based on appearance and analyzed whether voting was influenced by the appearance image; appearance image preferences for a female politician included the classic, dramatic, romantic and natural images. Through validations, the appearance image and competency had a causative factor that contributed to the acceptance of the politician image. The Classic Image demonstrated the strongest and most important image among the appearance images. As voters were more interested in the appearance image of a female politician, more emphasis and weight was on the appearance image during the voting selection process.

Molecular cloning, Expression and purification of Anthrax toxin from Bacillus anthracis

  • Yoon, Moon-Young
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.323-325
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    • 2002
  • Bacillus Anthracis is the causative agent of anthrax. The major virulence factors are a poly-D glutamic acid capsule and three-protein component exotoxin, which is collectively known as anthrax toxin, protective antigen (PA, 83 kDa), lethal factor (LF, 90 kDa), and edema factor (EF, 89 kDa). These three proteins individually have no known toxic activities, but in combination with PA form two toxins (lethal toxin and edema toxin), causing different pathogenic responses in animals and cultured cells. However, it remains to be elucidated for pathogenic mechanism of anthrax toxin. In this study, we constructed toxin component in bacterial overexpression system and purified the native toxin from Bacillus anthracis delta sterne F32 using FPLC system. Recombinant toxin showed high homogeneity and rapid purification processes. Also, this recombinant toxin was comparable to B. anthracis native toxin in terms of cytotoxic effects on cultured cell lines.

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