• Title/Summary/Keyword: time-dependent effect

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Against the Effect of Performance Duty Practicing in Psychological Factors of Security Guard (경호원의 심리요인이 임무수행에 미치는 영향)

  • Song, Sang wook;Roh, Jung gu
    • Journal of the Society of Disaster Information
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    • v.5 no.1
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    • pp.48-62
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    • 2009
  • Bodyguards always perform their duty with psychological burdens in their mind, not only because security situations are developed in various forms dependent on the surrounding environments or circumstances, but because bodyguards only take follow-up actions while the criminal decides time, place, and style of every attack. Thus, in the security situation, it is not uncommon for bodyguards to experience muscle rigidity, uncontrollable emotional elevation, difficulty in concentration, negative perception, frustration and enervation, which are caused by continuous physical/mental burdens, stimulations by various interpersonal behaviors or minute environmental stimulants. In conclusion, the result of performing security duties is related in the first place with the degree of the bodyguard's potential, in the second place with the degree of training and efficiency. And the result can also be changed by the way they control their negative psychological state of the moment when they carry out the skills they acquired. Maximizing the performance of the bodyguards by helping them overcome these psychological factors may be facilitated by detecting their psychological factors, understanding the causes, and training them in applying appropriate measures for overcoming these factors. When these measures are applied, the positive perception is indispensable that duties of protecting clients can be carried out successfully. No single measure can be declared to be more effective than the other because the effect of each measure is expressed differently by the individual characteristics of the bodyguards. However, it is important to select and apply the measures most appropriate to the bodyguard. Besides, they should devote themselves to the training with persistence because efficient implement of the measures for overcoming psychological factors takes a lot of time.

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Effect of metal alkoxide ratio and TiO2 composition on the synthesis of crystalline LAS glass by Sol-Gel method (졸-겔법에 의한 LAS계 결정화 유리합성에 미치는 금속 알콕사이드와 TiO2 조성비의 영향)

  • Seo, Kwang-Seok;Chun, Kyung-Soo
    • Analytical Science and Technology
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    • v.26 no.3
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    • pp.205-210
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    • 2013
  • For the synthesis of crystalline LAS glass by sol-gel method, the effect of operation conditions including metal alkoxide ratio, nucleating agent composition and heat treatment on the crystalline properties was experimentally investigated. The gelation time and crystallization temperature were proportionally affected by the mole ratio of TEOS in metal alkoxides solution. The addition of $TiO_2$ had an influence on the increasing of the gelation time, but the crystallization temperature was rarely dependent on the adding of nucleating agent. The crystallinity of LAS glass was improved by the nucleating agent under same heat treatment conditions.

Ethanol Elicits Inhibitory Effect on the Growth and Proliferation of Tongue Carcinoma Cells by Inducing Cell Cycle Arrest

  • Le, Thanh-Do;Do, Thi Anh Thu;Yu, Ri-Na;Yoo, Hoon
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.3
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    • pp.153-158
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    • 2012
  • Cellular effects of ethanol in YD-15 tongue carcinoma cells were assessed by MTT assay, caspase activity assay, Western blotting and flow cytometry. Ethanol inhibited the growth and proliferation of YD-15 cells in a dose- and time-dependent manner in an MTT assay. The effects of ethanol on cell cycle control at low percent range of ethanol concentration (0 to 1.5%), the condition not inducing YD-15 cell death, was investigated after exposing cells to alcohol for a certain period of time. Western blotting on the expression of cell cycle inhibitors showed that p21 and p27 was up-regulated as ethanol concentration increases from 0 to 1.5% whilst the cell cycle regulators, cdk1, cdk2, and cdk4 as well as Cyclin A, Cyclin B1 and Cyclin E1, were gradually down-regulated. Flow cytometric analysis of cell cycle distribution revealed that YD-15 cells exposed to 1.5% ethanol for 24 h was mainly arrested at G2/M phase. However, ethanol induced apoptosis in YD-15 cells exposed to 2.5% or higher percent of ethanol. The cleaved PARP, a marker of caspase-3 mediated apoptosis, and the activation of caspase-3 and -7 were detected by caspase activity assay or Western blotting. Our results suggest that ethanol elicits inhibitory effect on the growth and proliferation of YD-15 tongue carcinoma cells by mediating cell cycle arrest at G2/M at low concentration range and ultimately induces apoptosis under the condition of high concentration.

Mouse Nerve Growth Factor Facilitates the Growth of Interspinal Schwannoma Cells by Activating NGF Receptors

  • Liu, Shu Yi;Liu, Sheng Ze;Li, Yu;Chen, Shi
    • Journal of Korean Neurosurgical Society
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    • v.62 no.6
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    • pp.626-634
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    • 2019
  • Objective : Nerve growth factor (NGF) is a member of the neurotrophic factor family and plays a vital role in the physiological processes of organisms, especially in the nervous system. Many recent studies have reported that NGF is also involved in the regulation of tumourigenesis by either promoting or suppressing tumor growth, which depends on the location and type of tumor. However, little is known regarding the effect of NGF on interspinal schwannoma (IS). In the present study, we aimed to explored whether mouse nerve growth factor (mNGF), which is widely used in the clinic, can influence the growth of interspinal schwannoma cells (ISCs) isolated from IS in vitro. Methods : ISCs were isolated, cultured and identified by S-100 with immunofluorescence analysis. S-100-positive cells were divided into five groups, and separately cultured with various concentrations of mNGF (0 [phosphate buffered saline, PBS], 40, 80, 160, and 320 ng/mL) for 24 hours. Western blot and quantantive real time polymerase chain reaction (PCR) were applied to detect tyrosine kinase A (TrkA) receptor and p75 neurotrophin receptor ($p75^{NTR}$) in each group. Crystal violet staining was selected to assess the effect of mNGF (160 ng/mL) on ISCs growth. Results : ISCs growth was enhanced by mNGF in a dose-dependent manner. The result of crystal violet staining revealed that it was significantly strengthened the cells growth kinetics when cultured with 160 ng/mL mNGF compared to PBS group. Western blot and quantantive real time PCR discovered that TrkA receptor and mRNA expression were both up-regualated under the condition of mNGF, expecially in 160 ng/mL, while the exoression of $p75^{NTR}$ demonstrated no difference among groups. Conclusion : From these data, we conclude that exogenous mNGF can facilitate ISC growth by activating both TrkA receptor and $p75^{NTR}$. In addition, patients who are suffering from IS should not be administered mNGF in the clinic.

Simulation method of ground motion matching for multiple targets and effects of fitting parameter variation on the distribution of PGD

  • Wang, Shaoqing;Yu, Ruifang;Li, Xiaojun;Lv, Hongshan
    • Earthquakes and Structures
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    • v.16 no.5
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    • pp.563-573
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    • 2019
  • When generating spectrum-compatible artificial ground motion in engineering practices, the effect of the variation in fitting parameters on the distribution of the peak ground displacement (PGD) has not yet drawn enough attention. In this study, a method for simulating ground motion matching for multiple targets is developed. In this method, a frequency-dependent amplitude envelope function with statistical parameters is introduced to simulate the nonstationarity of the frequency in earthquake ground motion. Then, several groups of time-history acceleration with different temporal and spectral nonstationarities were generated to analyze the effect of nonstationary parameter variations on the distribution of PGD. The following conclusions are drawn from the results: (1) In the simulation of spectrum-compatible artificial ground motion, if the acceleration time-history is generated with random initial phases, the corresponding PGD distribution is quite discrete and an uncertain number of PGD values lower than the limit value are observed. Nevertheless, the mean values of PGD always meet the requirement in every group. (2) If the nonstationary frequencies of the ground motion are taken into account when fitting the target spectrum, the corresponding PGD values will increase. A correlation analysis shows that the change in the mean and the dispersion values, from before the frequencies are controlled to after, correlates with the modal parameters of the predominant frequencies. (3) Extending the maximum period of the target spectrum will increase the corresponding PGD value and, simultaneously, decrease the PGD dispersion. Finally, in order to control the PGD effectively, the ground motion simulation method suggested in this study was revised to target a specified PGD. This novel method can generate ground motion that satisfies not only the required precision of the target spectrum, peak ground acceleration (PGA), and nonstationarity characteristics of the ground motion but also meets the required limit of the PGD, improving engineering practices.

Temperature-dependent Differences in Heading Response at Different Growth Stages of Rice

  • Lee, HyeonSeok;Choi, MyoungGoo;Lee, YunHo;Hwang, WoonHa;Jeong, JaeHyeok;Yang, SeoYeong;Lim, YeonHwa;Lee, ChungGen;Choi, KyungJin
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.64 no.3
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    • pp.213-224
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    • 2019
  • There is an increasing frequency in the occurrence of abnormal weather phenomena such as sharp increases and decreases in temperature. Under these weather conditions, the heading time of rice changes unexpectedly, which poses problems in agriculture. Therefore, we investigated the effect of temperature on the heading response at different growth stages in rice. During the period from transplanting to heading, the plants were subjected to different temperature treatments, each for a 9-day period, to observe the heading response. For the heading date analysis, "heading date" was defined as the number of days from transplanting to the appearance of the first spikelet. We found that the influence of temperature increased in the order of rooting stage, followed by meiosis, early tillering, spikelet differentiation, and panicle initiation stage in all ecological types and cultivars. In particular, unlike the results reported previously, the effect of temperature on heading during the photo-sensitive period was very small. Meanwhile, the influence of temperature on vegetative growth response at different growth stages was not consistent with heading response. These results can be used as basic data for predicting the variation in heading date owing to temperature variation at each growth stage. In addition, we propose that the concept of day length should be included in determining the influence of temperature on the photo-sensitive period.

Intraocular Pressure and Neuroprotective Effect of water and ethanol extracts from Leaves of Acer palmatum thumb. of glaucoma in DBA2/J mice (녹내장 동물모델에서 단풍나무 잎 열수 및 에탄올 추출물의 안압 및 신경세포 보호 효과)

  • Oh, Tae Woo;Park, Kwang-Il;Ma, Jin Yeul
    • Herbal Formula Science
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    • v.29 no.2
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    • pp.93-103
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    • 2021
  • Objectives : This study was conducted to evaluate the Intraocular pressure (IOP) and retina neuroprotective effect of Acer palmatum thumb. extract in glaucoma of DBA2/J mice vivo model. Methods : The amount of change in intraocular pressure(IOP) was measured every two weeks for 30 weeks in the DBA2/J glaucoma animal model. The increased IOP were regrouping into drug treatment groups. EW and EE (1, 2 mg/㎖)extract was eye drop administered twice per day for 8 weeks. After administration of the extract, IOP was measured every 1 week at a fixed time for 8 weeks, and protein expression levels and serological changes related to retinal function were investigated. Results : The DBA2/J mice were IOP increased as time dependent, resulting in damage to the retinal function protein related in glaucoma animal model. However, administration of extracts from Leaves of Acer palmatum thumb. prevented an increase IOP, increased for Brn3α, PKCα, and OPN1SW. Additionally, the experssion of Aterocyte maker, GFAP was decreased in DBA2/J mice. Conclusions : These results demonstrate that both IOP and age can be considered in studies using DBA2/J mice and suggest that the extracts from Leaves of Acer palmatum thumb. regulating of IOP and expression of proteins related to retinal function.

Time trend of malaria in relation to climate variability in Papua New Guinea

  • Park, Jae-Won;Cheong, Hae-Kwan;Honda, Yasushi;Ha, Mina;Kim, Ho;Kolam, Joel;Inape, Kasis;Mueller, Ivo
    • Environmental Analysis Health and Toxicology
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    • v.31
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    • pp.3.1-3.11
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    • 2016
  • Objectives This study was conducted to describe the regional malaria incidence in relation to the geographic and climatic conditions and describe the effect of altitude on the expansion of malaria over the last decade in Papua New Guinea. Methods Malaria incidence was estimated in five provinces from 1996 to 2008 using national health surveillance data. Time trend of malaria incidence was compared with rainfall and minimum/maximum temperature. In the Eastern Highland Province, time trend of malaria incidence over the study period was stratified by altitude. Spatio-temporal pattern of malaria was analyzed. Results Nationwide, malaria incidence was stationary. Regionally, the incidence increased markedly in the highland region (292.0/100000/yr, p =0.021), and remained stationary in the other regions. Seasonality of the malaria incidence was related with rainfall. Decreasing incidence of malaria was associated with decreasing rainfall in the southern coastal region, whereas it was not evident in the northern coastal region. In the Eastern Highland Province, malaria incidence increased in areas below 1700 m, with the rate of increase being steeper at higher altitudes. Conclusions Increasing trend of malaria incidence was prominent in the highland region of Papua New Guinea, while long-term trend was dependent upon baseline level of rainfall in coastal regions.

The Effects of Head Mounted display on Time-on-task and Virtual Presence for Navigational Tasks in the Immersive Virtual Reality (실감형 가상현실에서 Head Mounted Display가 과제수행시간 및 가상실재감 요인에 미치는 영향)

  • Ryu, Jeeheon;Yu, Seungbeom
    • Science of Emotion and Sensibility
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    • v.19 no.3
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    • pp.71-80
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    • 2016
  • The purpose of this study was to examine the effects of display on time on tasks and virtual presence in the immersive virtual reality. Head mounted display (HMD) and monitor conditions were compared when the participants were asked to complete navigation tasks in a virtual classroom. Time on tasks and virtual presence were measured. Three factors of the virtual presence were applied as dependent variables such as 1) spatial presence, 2) involvement, and 3) realness. The results showed that HMD condition took longer time to finish tasks than monitor conditions. HMD condition showed significantly higher perception from all of the virtual presence factors. Interestingly, there was a significant interaction effect between the display conditions and presence factors. The relationship between display types and virtual presence factors were discussed for future study.

Multilevel Modeling Analysis of Developmental Changes in Early Adolescent Aggression and Family Factors (초기 청소년기 공격성의 발달적 변화와 가족 영향 요인에 대한 다층모형 분석)

  • Choi, Jung-Ah
    • The Journal of the Korea Contents Association
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    • v.14 no.2
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    • pp.294-307
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    • 2014
  • The purpose of this study is to examine the trajectory of early adolescent aggression and to assess the effects of perceived family factors on it. This study investigated the changes in aggression over time and the effects of three family factors, parental attachment, parental monitoring, and family conflict, on the changes using multilevel modeling. The data from Korea Youth Panel Survey(KYPS) of fourth graders who were followed over five years were analyzed. The results indicated that there was a significant average increase followed by a slight decrease in aggression over time; that is, the data followed a quadratic trend. Parental attachment, parental monitoring, and family conflict had significant time-independent effects on aggression, while only family conflict had a significant time-dependent effect on aggression. These results imply that family factors need to be emphasized in planning prevention and intervention programs to reduce aggression during adolescence.