• Title/Summary/Keyword: Mass changes

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Comparison of Heart Rate Variability Indices between Obstructive Sleep Apnea Syndrome and Primary Insomnia (폐쇄성 수면무호흡 증후군과 일차성 불면증에서 심박동률 변이도 지수의 비교)

  • Nam, Ji-Won;Park, Doo-Heum;Yu, Jaehak;Ryu, Seung-Ho;Ha, Ji-Hyeon
    • Sleep Medicine and Psychophysiology
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    • v.19 no.2
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    • pp.68-76
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    • 2012
  • Objectives: Sleep disorders cause changes of autonomic nervous system (ANS) which affect cardiovascular system. Primary insomnia (PI) makes acceleration of sympathetic nervous system (SNS) tone by sleep deficiency and arousal. Obstructive sleep apnea syndrome (OSAS) sets off SNS by frequent arousals and hypoxemias during sleep. We aimed to compare the changes of heart rate variability (HRV) indices induced by insomnia or sleep apnea to analyze for ANS how much to be affected by PI or OSAS. Methods: Total 315 subjects carried out nocturnal polysomnography (NPSG) were categorized into 4 groups - PI, mild, moderate and severe OSAS. Severity of OSAS was determined by apnea-hypopnea index (AHI). Then we selected 110 subjects considering age, sex and valance of each group's size [Group 1 : PI (mean age=$41.50{\pm}13.16$ yrs, AHI <5, n=20), Group 2 : mild OSAS (mean age=$43.67{\pm}12.11$ yrs, AHI 5-15, n=30), Group 3 : moderate OSAS (mean age $44.93{\pm}12.38$ yrs, AHI 16-30, n=30), Group 4 : severe OSAS (mean age=$45.87{\pm}12.44$ yrs, AHI >30, n=30)]. Comparison of HRV indices among the four groups was performed with ANCOVA (adjusted for age and body mass index) and Sidak post-hoc test. Results: We found statistically significant differences in HRV indices between severe OSAS group and the other groups (PI, mild OSAS and moderate OSAS). And there were no significant differences in HRV indices among PI, mild and moderate OSAS group. In HRV indices of PI and severe OSAS group showing the most prominent difference in the group comparisons, average RR interval were $991.1{\pm}27.1$ and $875.8{\pm}22.0$ ms (p=0.016), standard deviation of NN interval (SDNN) was $85.4{\pm}6.6$ and $112.8{\pm}5.4$ ms (p=0.022), SDNN index was $57.5{\pm}5.2$ and $87.6{\pm}4.2$ (p<0.001), total power was $11,893.5{\pm}1,359.9$ and $18,097.0{\pm}1,107.2ms^2$(p=0.008), very low frequency (VLF) was $7,534.8{\pm}1,120.1$ and $11,883.8{\pm}912.0ms^2$ (p=0.035), low frequency (LF) was $2,724.2{\pm}327.8$ and $4,351.6{\pm}266.9ms^2$(p=0.003). Conclusions: VLF and LF which were correlated with SNS tone showed more increased differences between severe OSAS group and PI group than other group comparisons. We could suggest that severe OSAS group was more influential to increased SNS activity than PI group.

Spatial effect on the diffusion of discount stores (대형할인점 확산에 대한 공간적 영향)

  • Joo, Young-Jin;Kim, Mi-Ae
    • Journal of Distribution Research
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    • v.15 no.4
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    • pp.61-85
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    • 2010
  • Introduction: Diffusion is process by which an innovation is communicated through certain channel overtime among the members of a social system(Rogers 1983). Bass(1969) suggested the Bass model describing diffusion process. The Bass model assumes potential adopters of innovation are influenced by mass-media and word-of-mouth from communication with previous adopters. Various expansions of the Bass model have been conducted. Some of them proposed a third factor affecting diffusion. Others proposed multinational diffusion model and it stressed interactive effect on diffusion among several countries. We add a spatial factor in the Bass model as a third communication factor. Because of situation where we can not control the interaction between markets, we need to consider that diffusion within certain market can be influenced by diffusion in contiguous market. The process that certain type of retail extends is a result that particular market can be described by the retail life cycle. Diffusion of retail has pattern following three phases of spatial diffusion: adoption of innovation happens in near the diffusion center first, spreads to the vicinity of the diffusing center and then adoption of innovation is completed in peripheral areas in saturation stage. So we expect spatial effect to be important to describe diffusion of domestic discount store. We define a spatial diffusion model using multinational diffusion model and apply it to the diffusion of discount store. Modeling: In this paper, we define a spatial diffusion model and apply it to the diffusion of discount store. To define a spatial diffusion model, we expand learning model(Kumar and Krishnan 2002) and separate diffusion process in diffusion center(market A) from diffusion process in the vicinity of the diffusing center(market B). The proposed spatial diffusion model is shown in equation (1a) and (1b). Equation (1a) is the diffusion process in diffusion center and equation (1b) is one in the vicinity of the diffusing center. $$\array{{S_{i,t}=(p_i+q_i{\frac{Y_{i,t-1}}{m_i}})(m_i-Y_{i,t-1})\;i{\in}\{1,{\cdots},I\}\;(1a)}\\{S_{j,t}=(p_j+q_j{\frac{Y_{j,t-1}}{m_i}}+{\sum\limits_{i=1}^I}{\gamma}_{ij}{\frac{Y_{i,t-1}}{m_i}})(m_j-Y_{j,t-1})\;i{\in}\{1,{\cdots},I\},\;j{\in}\{I+1,{\cdots},I+J\}\;(1b)}}$$ We rise two research questions. (1) The proposed spatial diffusion model is more effective than the Bass model to describe the diffusion of discount stores. (2) The more similar retail environment of diffusing center with that of the vicinity of the contiguous market is, the larger spatial effect of diffusing center on diffusion of the vicinity of the contiguous market is. To examine above two questions, we adopt the Bass model to estimate diffusion of discount store first. Next spatial diffusion model where spatial factor is added to the Bass model is used to estimate it. Finally by comparing Bass model with spatial diffusion model, we try to find out which model describes diffusion of discount store better. In addition, we investigate the relationship between similarity of retail environment(conceptual distance) and spatial factor impact with correlation analysis. Result and Implication: We suggest spatial diffusion model to describe diffusion of discount stores. To examine the proposed spatial diffusion model, 347 domestic discount stores are used and we divide nation into 5 districts, Seoul-Gyeongin(SG), Busan-Gyeongnam(BG), Daegu-Gyeongbuk(DG), Gwan- gju-Jeonla(GJ), Daejeon-Chungcheong(DC), and the result is shown

    . In a result of the Bass model(I), the estimates of innovation coefficient(p) and imitation coefficient(q) are 0.017 and 0.323 respectively. While the estimate of market potential is 384. A result of the Bass model(II) for each district shows the estimates of innovation coefficient(p) in SG is 0.019 and the lowest among 5 areas. This is because SG is the diffusion center. The estimates of imitation coefficient(q) in BG is 0.353 and the highest. The imitation coefficient in the vicinity of the diffusing center such as BG is higher than that in the diffusing center because much information flows through various paths more as diffusion is progressing. A result of the Bass model(II) shows the estimates of innovation coefficient(p) in SG is 0.019 and the lowest among 5 areas. This is because SG is the diffusion center. The estimates of imitation coefficient(q) in BG is 0.353 and the highest. The imitation coefficient in the vicinity of the diffusing center such as BG is higher than that in the diffusing center because much information flows through various paths more as diffusion is progressing. In a result of spatial diffusion model(IV), we can notice the changes between coefficients of the bass model and those of the spatial diffusion model. Except for GJ, the estimates of innovation and imitation coefficients in Model IV are lower than those in Model II. The changes of innovation and imitation coefficients are reflected to spatial coefficient(${\gamma}$). From spatial coefficient(${\gamma}$) we can infer that when the diffusion in the vicinity of the diffusing center occurs, the diffusion is influenced by one in the diffusing center. The difference between the Bass model(II) and the spatial diffusion model(IV) is statistically significant with the ${\chi}^2$-distributed likelihood ratio statistic is 16.598(p=0.0023). Which implies that the spatial diffusion model is more effective than the Bass model to describe diffusion of discount stores. So the research question (1) is supported. In addition, we found that there are statistically significant relationship between similarity of retail environment and spatial effect by using correlation analysis. So the research question (2) is also supported.

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  • Compilation of 104 Experimental Theses on the Antitumor and Immuno-activating therapies of Oriental Medicine (한의학의 항종양 면역치료에 관한 연구 -1990년 이후 발표된 실험논문을 중심으로-)

    • Kang Yeon Yee;Kim Tai Im;Park Jong Ho;Kim Sung Hoon;Park Jong Dai;Kim Dong Hee
      • Journal of Physiology & Pathology in Korean Medicine
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      • v.17 no.1
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      • pp.1-24
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      • 2003
    • This study was done to compile 104 experimental theses which are related to the antitumor and immuno-activating therapies between February 1990 through February 2002. Master's and doctoral theses were dassified by schools, degrees, materials, effects, experimental methods of antitumor and immunoactivity, and results. The following results were obtained from this study : 1. Classifying the theses by the school, 34.6% were presented by Daejeon University, 29.8% by Kyung-hee University and 11.5% by Won-kwang University. Of all theses, 51.0% were aimed for the doctoral degree and 43.3% were for the master's degree. All of three universities have their own cancer centers. 2. Classifying the theses by herb materials, complex prescription accounted for 60.3%, single herb accounted for 24.8% and herbal acupuncture accounted for 14.2%. Considering the key principles of the traditional medicine, complex prescription was much more thoroughly studied than single herb prescription. The results showed that the complex prescription had both antitumor activity and immuno-activating activity, which might reflects on multi-activation mechanisms by complex components. 3. Classifying the theses by the efficacy of herbs examined, in single herb, invigorating spleen and supplementing was 35.5%, expelling toxin and cooling was 29.0%, activating blood flow and removing blood stasis was 12.9%. In herbal acupuncture, invigorating spleen and supplementing was 52.9%, expelling toxin and cooling was 29.4%. In complex prescription, pathogen-free status was 41.9%, strengthening healthy qi to eliminate pathogen was 35.5%, strengthening healthy qi was 22.6%. It is presumed that the antitumor and immunoactivating therapy based on syndrome differentiation is the best way to develop oriental oncology. 4. Classifying the theses by antitumor experiments, cytotoxic effect was 48.1 %, survival time was 48.1 % and change of tumor size was 42.3%. Survival rate was not necessarily correlated with cytotoxicity. These data reflect the characteristic, wholistic nature of the oriental medicine which is based on BRM (biological response modifier). 5. Classifying the theses by immunoactivating experiments, hemolysin titer was 51.0%, hemagglutinin titer was 46.2% and NK cell's activity was 44.2%. In the future studies, an effort to elucidate specific molecular and cellular mechanisms of cytokine production in the body would be crucial. 6. Classifying the theses according to the data in terms of antitumor activity, 50% was evaluated good, 24.0% was excellent, and 15.5% have no effect. In an evaluation of immuno-activating activity, 35.9% was excellent and 18.0% showed a little effect. The index point, as described here, may helps to use experimental data for clinical trials. Changes in index points by varying dosage implicate the importance of oriental medical theory for prescription. 7. In 167 materials, IIP (immunoactivating index point, mean : 3.12±0.07) was significantly higher than AIP(antitumor index point, mean : 2.83±0.07). These data demonstrate that the effect of herb medicine on tumor activity depends more on immunoactivating activity than antitumor activity. This further implies that the development of herbal antitumor drugs must be preceded by the mechanistic understanding of immunoactivating effect. 8. After medline-searching tumor and herb-related articles from NCBI web site, we conclude that most of the studies are primarily focused on biomolecular mechanisms and/or pathways. Henceforth, we need to define the biomolecular mechanisms and/or pathways affected by herbs or complicated prescriptions. 9. Therefore, the most important point of oriental medical oncology is to conned between experimental results and clinical trials. For the public application of herbal therapy to cancer, it is critical to present the data to mass media. 10. To develop the relationship of experimental results and clinical trials, university's cancer clinic must have a long-range plan related to the university laboratories and, at the same time, a regular consortium for this relationship is imperative. 11. After all these efforts, a new type herbal medicine for cancer therapy which is to take care of the long-term administering and safety problem must be developed. Then, it would be expected that anti-tumor herbal acupuncture can improve clinical symptoms and quality of life (QOL) for cancer patients. 12. Finally, oriental medical cancer center must be constructed in NCC (National Cancer Center) or government agency for the development of oriental medical oncology which has international competitive power.

    A Study on Marketing of Cultured Laver Products (양식해태의 유통에 관한 조사 연구)

    • 유충열
      • The Journal of Fisheries Business Administration
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      • v.4 no.1_2
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      • pp.19-57
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      • 1973
    • Laver io one of the most necessary and seasonal items in Korean food from oldtimes. Laver is lagely eaten in dried form, and its supply depends entirely upon culture weeds. The history of laver culture in Korea about sixty or seventy years is older than in Japan. Significance of laver culture is divided into two aspects, one is food supply in the nation, and the other is export to other countries. Houses engaged in laver culture are about foully thousands, and laver production in 1972 is estimated as 1, 3 bitten sheets. (1 sheet is a dried laver of 20 cm sq, in the shape of paper) Especcially meaning of layer production is the concentration of labour input, and systematic management of labour. From around 1920, the method of laver culture was introduced by Japanese Imperialism for mono culture in shallow seas, and mass products of laver is provided to Japan market, DOMESTIC MARKET Fundamental consume function calculates at below, $D_{(68_71)}$=16354 $Y^{0.471}$ $P^{-1.0662}$ where D is total layer demand, Y income variable, P price variable. It means income elasticity is 476. in the whole country, and price elasticity is 1, 07. But generally income elasticity is higher in urban area than in rural area, as shown at 1, 3 in Seoul city. Expence of laver in house expenditure is mutually correlated with another expence, See Table 12 about the relative function. See Table 14 and 16 about the relation between the gathering and the changes of price in auction, wholesale and retail price support system is for two effects, one of which is constraint of the upper price, the other is rise of the lower price. Before the system control, the equation in three year average calculated as below, $Y_{b}$ =18, 907.7455+15435.9364 t (r=0.89) where the origin t=0 is the November and the units are month. Post the system control, $Y_{p}$ =30, 047.9636+1, 631.1721t (r=0.97) therefore, this system has an effect only on the rise of lower price, Average annual margins of laver products at four market levels according to the consumer spent is below. EXPORTING MARKET Japanese demand function of laver products is, Log D=5, 289+1, 108 Log Y-1, 395 Log P (r=0.987) where D is Japanese laver demand, Y income variable, P price variable. according to which income elasticity is 1. 1 and price elasticity is 1.4. Laver production in 1970 tile highest record till then, is estimated as six billion sheets. But the recent improvement of laver culture techniques, the production of seeds and freezing storage of seeds has been stabilized. Futher new culture farms have been developed by means of break- water fences or by floating culture method. These improvements have been backed up with increased demand of laver products. Import quantity and price of Korean laver products are restrained by three organizations, that is producer, distributor and consumer. This relationship calculated by regression equation shows that import is influenced only producer organization, at the sacrifice of consumer profit. For increase to export of laver products, we urgently require to open foreign trade of laver products for Japanese consumer, .and Japan has political responsibility to solve Korean laver structure. But with long run timeseries, as regards Japanese production and import quantity, importing function shows increasing trend as below, 250 million sheets <3, 947.1674+0.005 $L_{g}$ >) 600 million sheets where $L_{q}$ is relative production quantity of laver in Japan. (unit; 100 thousand sheets) Our Export effort should be put on the highly processed products whithin the restraind quote.ote.

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    Fate Analysis and Impact Assessment for Vehicle Polycyclic Aromatic Hydrocarbons (PAHs) Emitted from Metropolitan City Using Multimedia Fugacity Model (다매체거동모델을 이용한 대도시 자동차 배출 Polycyclic Aromatic Hydrocarbons (PAHs) 거동 해석 및 영향평가)

    • Rhee, Gahee;Hwangbo, Soonho;Yoo, ChangKyoo
      • Korean Chemical Engineering Research
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      • v.56 no.4
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      • pp.479-495
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      • 2018
    • This study was carried out to research the multimedia fate modeling, concentration distribution and impact assessment of polycyclic aromatic hydrocarbons (PAHs) emitted from automobiles, which are known as carcinogenic and mutation chemicals. The amount of emissions of PAHs was determined based on the census data of automobiles at a target S-city and emission factors of PAHs, where multimedia fugacity modeling was conducted by the restriction of PAHs transfer between air-soil at the impervious area. PAHs' Concentrations and their distributions at several environmental media were predicted by multimedia fugacity model (level III). The residual amounts and the distributions of PAHs through mass transfer of PAHs between environment media were used to assess the health risk of PAHs at unsteady state (level IV), where the sensitivity analyses of the model parameter of each variable were conducted based on Monte Carlo simulation. The experimental result at S-city showed that Fluoranthene among PAHs substances are the highest residual concentrations (60%, 53%, 32% and 34%) at all mediums (atmospheric, water, soil, sediment), respectively, where most of the PAHs were highly accumulated in the sediment media (more than 80%). A result of PAHs concentration changes in S-city over the past 34 years identified that PAHs emissions from all environmental media increased from 1983 to 2005 and decreased until 2016, where the emission of heavy-duty vehicle including truck revealed the largest contribution to the automotive emissions of PAHs at all environment media. The PAHs concentrations in soil and water for the last 34 years showed the less value than the legal standards of PAHs, but the PAHs in air exceeded the air quality standards from 1996 to 2016. The result of this study is expected to contribute the effective management and monitoring of toxic chemicals of PAHs at various environment media of Metropolitan city.

    Planktic Foraminiferal Assemblages of Core Sediments from the Korea Strait and Paleoceanographic Changes (대한해협 코아 퇴적물의 부유성 유공충 군집 특성과 고해양 환경 변화)

    • Kang, So-Ra;Lim, D.I.;Rho, K.C.;Jung, H.S.;Choi, J.Y.;Yoo, H.S.
      • Journal of the Korean earth science society
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      • v.27 no.4
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      • pp.464-474
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      • 2006
    • The paleoceanography since 14 ka was reconstructed based on the planktic foraminiferal assemblages of core sediments from the outer shelf of the Korea Strait. Planktic foraminifera in the core sediments can be divided into four assemblages: A, B, C, and D. Assemblage A consists mainly of Globigerinoides ruber group and Globigerinoides conglobatus with low abundance (less than 10%), indicating the tropical-subtropical water mass. Assemblage B is composed of Pulleniatina obliquiloculata and Neogloboquadrina dutertrei, the indicator of Kuroshio Current, and shows the aspect of the inflow of the Tsushima Current into the Korea Strait. Assemblage C yields polar-subpolar species, mainly Neogloboquadrina incompta and N. pachyderma. It decreases upward of the core. Assemblage D contains coastal water species such as Globigerina bulloides and G. quinqueloba. It is abundant in the lower to middle region of the core. From the analysis of distributions of each assemblage and the result of age datings in the core, it is suggested that the Korea Strait played a role of channelling the East China Sea and the East Sea after the LGM (ca. 14 ka). During this time, the coastal water, affected by fresh waters originated from the river systems of China and/ or the Korean Peninsula, flourished around the Korea Strait and theses coastal water might entered to the East Sea. Around 8.5 ka, the effect of the Tsushima Current started to strengthen in this region, and the present current system seems to be formed at about $7{\sim}6ka$.

    Psychological benefits of bench-step aerobics program in overweight or obese adult women: its effects on anger, exercise self-efficacy, exercise-related affect, and body image (과체중 및 비만 성인 여성 대상 스텝운동 프로그램의 심리적 효과: 분노, 운동관련 자기 효능감, 운동관련 정서 및 신체상에 미치는 효과)

    • Lee, Mi-Ra;Kim, Wan-Soo
      • Korean Journal of Health Education and Promotion
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      • v.24 no.5
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      • pp.119-135
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      • 2007
    • Objectives: The efficacy, feasibility, and safety of bench-step aerobics (BSA) program in overweight or obese Korean adult women have been implied. However, there has been almost no evidence for its psychological benefits. As such, the purpose of this study was to investigate the psychological benefits of BSA program in overweight or obese (body mass index ${\geq}\;23\;kg/m^2$) Korean adult women. Method: Anger, exercise self-efficacy, exercise-related affect, and body image of overweight or obese women who participated in a 12-week BSA program (n=15) were compared with those of their counterparts in the control group (n=13). Subjects were selected among public health center visitors and those recruited by putting an advertisement in local newspapers and the public health center homepage. Data from the exercise and control groups were collected before and after the 12-week BSA program (from August to November in 2006) at the public health centers. The exercise program consisted of 45 to 60 min moderate-intensity (40/50 to 50/60% of their hear rate reserve) BSA performed for 3 days a week. Results: After the BSA program, body image of the subjects in the exercise group was significantly improved and there was a significant difference between the exercise and control groups. Anger, exercise self-efficacy, and exercise-related affect were improved after the BSA program but the changes did not reach the level of statistical significance and there were no significant differences between the exercise and control groups. Conclusions: In conclusion, BSA appears to significantly enhance body image in overweight or obese Korean adult women but its effects on anger, exercise self-efficacy, and exercise-related affect do not appear to be statistically significant. Further studies involving different subjects, particularly whose levels of anger are high or whose levels of exercise-related affect are low to exclude the influence of the ceiling or floor effect, are warranted in a randomized controlled design.

    Gallbladder Ejection Fraction Using $^{99m}Tc$-DISIDA Scan in Diabetic Autonomic Neuropathy (당뇨병성 자율 신경병증에서 $^{99m}Tc$-DISIDA를 이용한 담낭 배출율에 관한 연구)

    • Kim, Seong-Jang;Kim, In-Ju;Kim, Yong-Ki;An, Jun-Hyup;Yoo, Seok-Dong
      • The Korean Journal of Nuclear Medicine
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      • v.34 no.1
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      • pp.55-61
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      • 2000
    • Purpose: We performed this study to evaluate the changes of gallbladder ejection fraction (GBEF) in diabetic patients with or without autonomic neuropathy. Materials and Methods: This study included 37 diabetic patients (25 women, 12 men, mean age 51 years) and 24 normal controls (10 women, 14 men, mean age 38 years). After intravenous injection of 185 MBq of $^{99m}Tc$-DISIDA, serial anterior abdominal images were acquired before and after fatty meal. Regions of interest were applied on gallbladder and right hepatic lobe on 60 and 90 minute images to calculate GBEF. Results: GBEF was significantly reduced in diabetes with autonomic neuropathy ($43{\pm}12.3%$) and without autonomic neuropathy ($57.5{\pm}13.2%$) compared with normal controls ($68{\pm}11.6%$, p<0.05). And also, GBEF was significantly reduced in diabetes with autonomic neuropathy compared with diabetes without autonomic neuropathy (p<0.05). Fasting blood glucose level, age, sex, hemoglobin Alc, body mass index, serum lipid level were not different in these two diabetic patient groups (p>0.05). When 50.2% of GBEF was used as the criteria for diabetic autonomic neuropathy, the sensitivity and specificity were 80%, 76.5%, respectively. The area under receiver operating characteristic curve was 0.846. Conclusion: GBEF of diabetic patients with autonomic neuropathy was significantly reduced than that of diabetic patients without autonomic neuropathy.

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    Ecosysteme de I′Etang de Berre (Mediterranee nord-occidentale) : Caracteres Generales Physiques, Chimiques et Biologiques

    • Kim, Ki-Tai
      • Korean Journal of Environmental Biology
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      • v.22 no.2
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      • pp.247-258
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      • 2004
    • Climatological, hydrological and planktonical research studies, measurements of primary production and photosynthetic efficiency from December 1976 to December 1978 have been carried out in two brackish lakes: Lake Etang de Berre and Lake Etang de Vaine located in the French Mediterranean coast, in the region of Carry-le-Rouet located on the north-west Mediterranean near Marseilles, and in fresh water inflows from 4 Rivers (Touloubre, Durance, Arc, Durancole) to Lake Etang de Berre. Physico-chemical parameters were measured for this study: water temperature, salinity, density, pH, alcalinity, dissolved oxygen (% saturation), phosphate, nitrate, nitrite, silicate etc. Diverse biological parameters were also studied: photosynthetic pigments, phaeopigments, specific composition and biomass of phytoplankton, primary pelagic production etc. Climatical factors were studied: air-temperature, solar-radiation, evaporation, direction (including strength) of winds, precipitation and freshwater volume of the four rivers. The changes in Lake ‘Etang de Berre’ ecosystem depend on the quality of the water in the Durance River, and on the effects of seawater near the entrance of the Caronte Canal. The water quality of the lake varies horizontally and vertically as a result of atmospheric phenomena, maritime currents and tides. The distribution of water temperatures is generally heterogeneous. Southeasterly winds and the Northeasterly Mistral wind are important in the origins of circulated and mixed water masses. These winds are both frequent and strong. They have, as a result, a great effect on the water environment of Lake Etang de Berre. In theory, the annual precipitation in this region is well over eight times the water mass of the lake. The water of the Durance River flows into Lake Etang de Berre through the EDF Canal, amounting to 90% of the precipitation. However, reduction of rainfall in dry seasons has a serious effect on the hydrological characteristics of the lake. The temperature in the winter is partially caused by the low temperature of fresh water, particularly that of the Durance River. The hydrological season of fresh and brackish water is about one month ahead of the hydrological season of sea water in its vicinity. The salinity of Lake Etang de Berre runs approximately 3$\textperthousand$, except at lower levels and near the entrance to the Caronte Canal. However, when the volume of the Durance River water is reduced in the summer and fall, the salinity rises to 15$\textperthousand$. In the lake, the ratio of fresh water to sea water is six to one (6:1). The large quantities of seston conveyed by rivers, particularly the Durance diversion, strongly reduce the transparency in the brackish waters. Although the amount of sunshine is also notable, transparency is slight because of the large amount of seston, carried chiefly by Tripton in the fresh water of the Durance River. Therefore, photosynthesis generally occurs only in the surface layer. The transparency progressively increases from freshwater to open seawater, as mineral particles sink to the bottom (about 1.7kg $m^{-2}a^{-1}$ on the average in brackish lakes). The concentration of dissolved oxygen and the rate of oxygen saturation in seawater (Carry-le-Rouet) ranged from 5.0 to 6.0 $m\ell$ㆍ.$1^{-1}$, and from 95 to 105%, respectively. The amount of dissolved oxygen in Etang de Berre oscillated between 2.9 and 268.3%. The monographs of phosphate, nitrate, nitrite and silicate were published as a part of a study on the ecology of phytoplankton in these environments. Horizontal and vertical distributions of these nutriments were studied in detail. The recent diversion of the Durance River into Lake Etang de Berre has effected a fundamental change in this formerly marine environment, which has had a great impact in its plankton populations. A total of 182 taxa were identified, including 111 Bacillariophyceae, 44 Chlorophyceae, and 15 Cyanophyceae. The most abundant species are small freshwater algae, mainly Chlorophyceae. The average density is about $10^{8}$ cells $1^{-1}$ in Lake Etang de Berre, and about double that amount in Lake Etang de Vaine. Differences in phytoplankton abundance and composition at the various stations or at various depths are slight. Cell biovolume V (equivalent to true biomass), plasma volume VP (‘useful’ biomass) and, simultaneously. the cell surface area S and S/V ratio through the measurement of cell dimensions were computed as the parameters of phytoplankton productivity and metabolism. Pigment concentrations are generally very high on account of phytoplankton blooms by Cyanophyceae, Chlorophyceae and Cryptophyceae. On the other hand, in freshwaters and marine waters, pigment concentrations are comparatively low and stable, showing slight annual variation. The variations of ATP concentration were closely related to those of chlorophyll a and phytoplankton blooms only in marine waters. The carbon uptake rates ranged between 38 and 1091 mg$Cm^{-2}d^{-1}$, with an average surface value of 256 mg; water-column carbon-uptake rates ranged between 240 and 2310 mg$Cm^{-2}d^{-1}$, with an average of 810, representing 290 mg$Cm^{-2}$, per year 45 000 tons per year of photosynthetized carbon for the whole lake. Gross photosynthetic production measured by the method of Ryther was studied over a 2-year period. The values obtained from marine water(Carry-le-Rouet) ranged from 23 to 2 337 mg$Cm^{-2}d^{-1}$, with a weighted average of 319, representing about 110 gCm$^{-2}$ per year. The values in brakish water (Etang de Berre) ranged from 14 to 1778 mg$Cm^{-2}d^{-1}$, with a weighted average of 682, representing 250 mg$Cm^{-2}$ per year and 38 400 tons per year of photosynthesized carbon for the whole lake.

    Development of an Efficient Screening Method for Resistance of Chili Pepper Plants to Meloidogyne incognita (뿌리혹선충 Meloidogyne incognita에 대한 저항성 고추를 선발하기 위한 효율적인 검정법 확립)

    • Hwang, Sung Min;Jang, Kyoung Soo;Choi, Yong Ho;Choi, Gyung Ja
      • Horticultural Science & Technology
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      • v.34 no.2
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      • pp.282-293
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      • 2016
    • Root-knot nematodes (Meloidogyne spp.) are major plant pathogens that cause reductions in yield and quality of several solanaceous crops, including pepper (Capsicum spp.). These losses can be averted through planting of resistant cultivars. Plants are defined as resistant when they suppress nematode reproduction. In this study, the resistance degrees of 102 commercial cultivars of chili pepper (Capsicum annuum) to a root-knot nematode, Meloidogyne incognita, were evaluated by comparing the number of egg masses on their roots to those of 'PR huimangchan', a highly susceptible cultivar that exhibited the most egg masses of the chili pepper cultivars evaluated. Among these cultivars, forty-four (43.1%) showed resistance to M. incognita and eighteen (17.6%) were moderately resistant. The other cultivars (39.3%) were determined to be susceptible. For further study, six chili pepper cultivars (i.e., Gangryeokjosenggeon, Shinsegae, Muhanjilju, PR Bulrocho, PR Huimangchan, and Jjang) with different levels of resistance to the nematode were selected. Changes in resistance of the six cultivars under several conditions, such as inoculum concentration, plant growth stage, and cultivation period after transplanting were investigated. We found that an efficient screening method for resistance of chili pepper to M. incognita is to transplant the chili pepper seedlings 7 days before inoculation, to inoculate 28-day-old plants with M. incognita by loading 5,000 eggs per plant into the pot of soil, to cultivate the plants in a greenhouse ($25{\pm}5^{\circ}C$) for 45-60 days, to measure the number of egg masses on roots of the seedlings, and then to determine the resistance response of the plants by comparing the number of egg masses on the roots with a reference-susceptible cultivar 'PR huimangchan'.


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