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Changes Occurred in Protein and Amino Acid Compositions during Postmortem Aging of White and Dark Muscle of Yellowtail at $2^{\circ}C$ (방어 보통육과 혈합육의 단백질 및 아미노산조성의 사후변화)

  • KIM Chang-Yang;CHOI Yeung-Joon;PYEUN Jae-Hyeung
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.15 no.2
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    • pp.123-136
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    • 1982
  • We investigated the changes in protein and free amino acid compositions of the muscles, and amino acid composition of the muscle proteins during postmortem storage of dorsal white and lateral dark muscles of Yellowtail, Seriola quinqueradita, which were kept at $2^{\circ}C$. We present an extensive discussion on the relationship between the changes of freshness and those of protein compositions in the white and the dark muscle of the red-fleshed fish by analyzing polyacrylamide gel electrophoretograms of $NaDodSO_4-solubilized$ sarcoplasmic and myofibrillar proteins extracted from the both muscles. By assessing K-value, total volatile basic nitrogen and pH value as a criterion of freshness, we found that the dark muscle undergoes a more rapid decrease in its freshness compared to that of the white muscle. The contents of the sarcoplasmic and the myofibrillar protein were decreased with postmortem aging of the muscles while those of the residual intracellular protein were increased, and these changes were somewhat faster in the dark muscle than in the white muscle. From the analysis of the electrophoretograms and their densitograms, we found that the sarcoplasmic proteins of the white and the dark muscle were respectively composed of 16 and 12 components. The sarcoplasmic protein of the white muscle lapsed for 10 days showed an increase of 18,000 and 41,000 dalton components, and a gradual decrease of 23,000 and 23,500 dalton components, whereas the sarcoplasmic protein of the dark muscle lapsed for 9 days showed a decrease of 49,000 dalton component, an appearence of a newly formed component of 47,000 dalton, and a disappearance of 26,000 dalton component. The electrophoretograms of the myofibrillar proteins shelved that the white and the dark muscle were composed of 17 and 16 components, respectively. Depending on the lapsed time of postmortem under the controlled condition, the myofibrillar proteins of the white muscle showed an increase of 40,000 dalton component, a gradual decrease of 37,500 dalton component, an appearance of a newly forming component of 32,000 dalton and a disappearance of 26,000 dalton component. On the other hand, the myofibrillar proteins of the dark muscle showed an increase of 58,000 and 64,000 dalton bands, a disappearance of light chain-2 protein and an appearance of a newly forming protein of 32,000 dalton. These changes on the electrophoretic patterns in the dark muscle were more rapid than those in the white muscle. In almost all of the cases, we observed that the changes in the sarcoplasmic protein were faster than those in the myofibrillar protein. The analysis of amino acid of the both muscle proteins showed that the white muscle was rich in glutamic acid, aspartic acid, leucine, arginine, lysine, etc. but was poor in proline and tryptophan. No significant difference was found in the amino acid composition of protein of both the white and the dark muscles. The sample of white muscle lapsed for 10 days shows a remarkable decrease in glutamic and aspartic acids, while that of the dark muscle lapsed for 9 days shows an appreciable decrease in alanine, glycine and arginine. The free amino acid compositions of the white and the dark muscles are respectively characterized with $63\%$ of histidine and $67\%$ of taurine with respect to the total free amino acids of the yellowtail at-death, respectively. The white muscle lapsed for 10 days showed an increase of histidine, valine and taurine, and a slight decrease of alanine, leucine and glycine. The dark muscle lapsed for 9 days shelved an increase of taurine, phenylalanine and glycine, and a decrease of histidine, alanine and serine.

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Flow Resistance and Modeling Rule of Fishing Nets -1. Analysis of Flow Resistance and Its Examination by Data on Plane Nettings- (그물어구의 유수저항과 근형수칙 -1. 유수저항의 해석 및 평면 그물감의 자료에 의한 검토-)

  • KIM Dae-An
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.28 no.2
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    • pp.183-193
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    • 1995
  • Assuming that fishing nets are porous structures to suck water into their mouth and then filtrate water out of them, the flow resistance N of nets with wall area S under the velicity v was taken by $R=kSv^2$, and the coefficient k was derived as $$k=c\;Re^{-m}(\frac{S_n}{S_m})n(\frac{S_n}{S})$$ where $R_e$ is the Reynolds' number, $S_m$ the area of net mouth, $S_n$ the total area of net projected to the plane perpendicular to the water flow. Then, the propriety of the above equation and the values of c, m and n were investigated by the experimental results on plane nettings carried out hitherto. The value of c and m were fixed respectively by $240(kg\cdot sec^2/m^4)$ and 0.1 when the representative size on $R_e$ was taken by the ratio k of the volume of bars to the area of meshes, i. e., $$\lambda={\frac{\pi\;d^2}{21\;sin\;2\varphi}$$ where d is the diameter of bars, 21 the mesh size, and 2n the angle between two adjacent bars. The value of n was larger than 1.0 as 1.2 because the wakes occurring at the knots and bars increased the resistance by obstructing the filtration of water through the meshes. In case in which the influence of $R_e$ was negligible, the value of $cR_e\;^{-m}$ became a constant distinguished by the regions of the attack angle $ \theta$ of nettings to the water flow, i. e., 100$(kg\cdot sec^2/m^4)\;in\;45^{\circ}<\theta \leq90^{\circ}\;and\;100(S_m/S)^{0.6}\;(kg\cdot sec^2/m^4)\;in\;0^{\circ}<\theta \leq45^{\circ}$. Thus, the coefficient $k(kg\cdot sec^2/m^4)$ of plane nettings could be obtained by utilizing the above values with $S_m\;and\;S_n$ given respectively by $$S_m=S\;sin\theta$$ and $$S_n=\frac{d}{I}\;\cdot\;\frac{\sqrt{1-cos^2\varphi cos^2\theta}} {sin\varphi\;cos\varphi} \cdot S$$ But, on the occasion of $\theta=0^{\circ}$ k was decided by the roughness of netting surface and so expressed as $$k=9(\frac{d}{I\;cos\varphi})^{0.8}$$ In these results, however, the values of c and m were regarded to be not sufficiently exact because they were obtained from insufficient data and the actual nets had no use for k at $\theta=0^{\circ}$. Therefore, the exact expression of $k(kg\cdotsec^2/m^4)$, for actual nets could De made in the case of no influence of $R_e$ as follows; $$k=100(\frac{S_n}{S_m})^{1.2}\;(\frac{S_m}{S})\;.\;for\;45^{\circ}<\theta \leq90^{\circ}$$, $$k=100(\frac{S_n}{S_m})^{1.2}\;(\frac{S_m}{S})^{1.6}\;.\;for\;0^{\circ}<\theta \leq45^{\circ}$$

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Research on the Methods and Proper Provisions for Rotational Irrigation (윤환관개방법과 적정시설 연구)

  • 유한열
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.13 no.1
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    • pp.2191-2205
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    • 1971
  • In this research, Nong-rim No. 6 was adopted as a test variety of rice. Rice seedlings were transplanted on June 14, 1970. Roots were settled into soil on June 20 and a total number of days irrigated of $21cm{\times}21cm$ and an area of $9.9m^2$ for a test plot were accepted, planting 70 stumps of rice in a test plot. The soil in test plots are classified by soil test as oam, and its chemical contents are as shown in Table 3. Irrigation water was secured by pumping from the Sudun stream that originates at the Suho reservoir. Accordingly, the qualities of irrigation. water are considered to be the same as those of water stored in the Suho reservoir. There were 54 days of intermittent rainfalls in total during the whole 110-day period of irrigation. As a result, it is likely that the growth of rice plants was influenced by rainfall at a comparatively great degree. In order to measure the amounts of water consumption, infiltrometers, measuring devices for the decreases of water depths and lycimeters were provided. As a result of measurements, an average daily rate of infiltration was observed to be 14mm/day. It is expected from this research that the effect of increased yield will be secured by supplying optimum amounts of water for irrigation on proper times, and that the amounts of water consumption for irrigation can be saved by applying suitable irrigation methods. The test results obtained are summarized as follows: 1. Yields produced in the test plots of continuous irrigation are lower than those in the test plots of rotational irrigation, i.e., yields produced at the test plots irrigatied once in a period of 8 days are higher by 27% in average than those produced at test plots of continuous irrigation. 2. The amounts of irrigation water for test plots, which have a clay layer of 9cm in thickness and vynil diaphragm without holes, are saved by about 52% in comparison with ordinary test plots. 3. Ears are sprouted 5 days earlier at continuous irrigation plots as compared with other test plots. 4. It seems that there are growing stages of rice plants such as those of forming and sprouting of ears, in which the amounts of irrigation water are consumed more in comparison with the other stages. Therefore, it may be possible to increase of decrease the amount of irrigation water, according to the growing stage of rice plant, so as to save irrigation water.

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The Effects of the Computer Aided Innovation Capabilities on the R&D Capabilities: Focusing on the SMEs of Korea (Computer Aided Innovation 역량이 연구개발역량에 미치는 효과: 국내 중소기업을 대상으로)

  • Shim, Jae Eok;Byeon, Moo Jang;Moon, Hyo Gon;Oh, Jay In
    • Asia pacific journal of information systems
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    • v.23 no.3
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    • pp.25-53
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    • 2013
  • This study analyzes the effect of Computer Aided Innovation (CAI) to improve R&D Capabilities empirically. Survey was distributed by e-mail and Google Docs, targeting CTO of 235 SMEs. 142 surveys were returned back (rate of return 60.4%) from companies. Survey results from 119 companies (83.8%) which are effective samples except no-response, insincere response, estimated value, etc. were used for statistics analysis. Companies with less than 50billion KRW sales of entire researched companies occupy 76.5% in terms of sample traits. Companies with less than 300 employees occupy 83.2%. In terms of the type of company business Partners (called 'partners with big companies' hereunder) who work with big companies for business occupy 68.1%. SMEs based on their own business (called 'independent small companies') appear to occupy 31.9%. The present status of holding IT system according to traits of company business was classified into partners with big companies versus independent SMEs. The present status of ERP is 18.5% to 34.5%. QMS is 11.8% to 9.2%. And PLM (Product Life-cycle Management) is 6.7% to 2.5%. The holding of 3D CAD is 47.1% to 21%. IT system-holding and its application of independent SMEs seemed very vulnerable, compared with partner companies of big companies. This study is comprised of IT infra and IT Utilization as CAI capacity factors which are independent variables. factors of R&D capabilities which are independent variables are organization capability, process capability, HR capability, technology-accumulating capability, and internal/external collaboration capability. The highest average value of variables was 4.24 in organization capability 2. The lowest average value was 3.01 in IT infra which makes users access to data and information in other areas and use them with ease when required during new product development. It seems that the inferior environment of IT infra of general SMEs is reflected in CAI itself. In order to review the validity used to measure variables, Factors have been analyzed. 7 factors which have over 1.0 pure value of their dependent and independent variables were extracted. These factors appear to explain 71.167% in total of total variances. From the result of factor analysis about measurable variables in this study, reliability of each item was checked by Cronbach's Alpha coefficient. All measurable factors at least over 0.611 seemed to acquire reliability. Next, correlation has been done to explain certain phenomenon by correlation analysis between variables. As R&D capabilities factors which are arranged as dependent variables, organization capability, process capability, HR capability, technology-accumulating capability, and internal/external collaboration capability turned out that they acquire significant correlation at 99% reliability level in all variables of IT infra and IT Utilization which are independent variables. In addition, correlation coefficient between each factor is less than 0.8, which proves that the validity of this study judgement has been acquired. The pair with the highest coefficient had 0.628 for IT utilization and technology-accumulating capability. Regression model which can estimate independent variables was used in this study under the hypothesis that there is linear relation between independent variables and dependent variables so as to identify CAI capability's impact factors on R&D. The total explanations of IT infra among CAI capability for independent variables such as organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability are 10.3%, 7%, 11.9%, 30.9%, and 10.5% respectively. IT Utilization exposes comprehensively low explanatory capability with 12.4%, 5.9%, 11.1%, 38.9%, and 13.4% for organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability respectively. However, both factors of independent variables expose very high explanatory capability relatively for technology-accumulating capability among independent variable. Regression formula which is comprised of independent variables and dependent variables are all significant (P<0.005). The suitability of regression model seems high. When the results of test for dependent variables and independent variables are estimated, the hypothesis of 10 different factors appeared all significant in regression analysis model coefficient (P<0.01) which is estimated to affect in the hypothesis. As a result of liner regression analysis between two independent variables drawn by influence factor analysis for R&D capability and R&D capability. IT infra and IT Utilization which are CAI capability factors has positive correlation to organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability with inside and outside which are dependent variables, R&D capability factors. It was identified as a significant factor which affects R&D capability. However, considering adjustable variables, a big gap is found, compared to entire company. First of all, in case of partner companies with big companies, in IT infra as CAI capability, organization capability, process capability, human resources capability, and technology capability out of R&D capacities seems to have positive correlation. However, collaboration capability appeared insignificance. IT utilization which is a CAI capability factor seemed to have positive relation to organization capability, process capability, human resources capability, and internal/external collaboration capability just as those of entire companies. Next, by analyzing independent types of SMEs as an adjustable variable, very different results were found from those of entire companies or partner companies with big companies. First of all, all factors in IT infra except technology-accumulating capability were rejected. IT utilization was rejected except technology-accumulating capability and collaboration capability. Comprehending the above adjustable variables, the following results were drawn in this study. First, in case of big companies or partner companies with big companies, IT infra and IT utilization affect improving R&D Capabilities positively. It was because most of big companies encourage innovation by using IT utilization and IT infra building over certain level to their partner companies. Second, in all companies, IT infra and IT utilization as CAI capability affect improving technology-accumulating capability positively at least as R&D capability factor. The most of factor explanation is low at around 10%. However, technology-accumulating capability is rather high around 25.6% to 38.4%. It was found that CAI capability contributes to technology-accumulating capability highly. Companies shouldn't consider IT infra and IT utilization as a simple product developing tool in R&D section. However, they have to consider to use them as a management innovating strategy tool which proceeds entire-company management innovation centered in new product development. Not only the improvement of technology-accumulating capability in department of R&D. Centered in new product development, it has to be used as original management innovative strategy which proceeds entire company management innovation. It suggests that it can be a method to improve technology-accumulating capability in R&D section and Dynamic capability to acquire sustainable competitive advantage.

The Usefulness of Product Display of Online Store by the Product Type of Usage Situation - Focusing on the moderate effect of the product portability - (사용상황별 제품유형에 따른 온라인 점포 제품디스플레이의 유용성 - 제품 휴대성의 조절효과를 중심으로 -)

  • Lee, Dong-Il;Choi, Seung-Hoon
    • Journal of Distribution Research
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    • v.16 no.2
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    • pp.1-24
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    • 2011
  • 1. Introduction: Contrast to the offline purchasing environment, online store cannot offer the sense of touch or direct visual information of its product to the consumers. So the builder of the online shopping mall should provide more concrete and detailed product information(Kim 2008), and Alba (1997) also predicted that the quality of the offered information is determined by the post-purchase consumer satisfaction. In practice, many fashion and apparel online shopping malls offer the picture information with the product on the real person model to enhance the usefulness of product information. On the other virtual product experience has been suggested to the ways of overcoming the online consumers' limited perceptual capability (Jiang & Benbasat 2005). However, the adoption and the facilitation of the virtual reality tools requires high investment and technical specialty compared to the text/picture product information offerings (Shaffer 2006). This could make the entry barrier to the online shopping to the small retailers and sometimes it could be demanding high level of consumers' perceptual efforts. So the expensive technological solution could affects negatively to the consumer decision making processes. Nevertheless, most of the previous research on the online product information provision suggests the VR be the more effective tools. 2. Research Model and Hypothesis: Presented in

    , research model suggests VR effect could be moderated by the product types by the usage situations. Product types could be defined as the portable product and installed product, and the information offering type as still picture of the product, picture of the product with the real-person model and VR. 3. Methods and Results: 3.1. Experimental design and measured variables We designed the 2(product types) X 3(product information types) experimental setting and measured dependent variables such as information usefulness, attitude toward the shopping mall, overall product quality, purchase intention and the revisiting intention. In the case of information usefulness and attitude toward the shopping mall were measured by multi-item scale. As a result of reliability test, Cronbach's Alpha value of each variable shows more than 0.6. Thus, we ensured that the internal consistency of items. 3.2. Manipulation check The main concern of this study is to verify the moderate effect by the product type of usage situation. indicates that our experimental manipulation of the moderate effect of the product type was successful. 3.3. Results As
    indicates, there was a significant main effect on the only one dependent variable(attitude toward the shopping mall) by the information types. As predicted, VR has highest mean value compared to other information types. Thus, H1 was partially supported. However, main effect by the product types was not found. To evaluate H2 and H3, a two-way ANOVA was conducted. As
    indicates, there exist the interaction effects on the three dependent variables(information usefulness, overall product quality and purchase intention) by the information types and the product types. As predicted, picture of the product with the real-person model has highest mean among the information types in the case of portable product. On the other hand, VR has highest mean among the information types in the case of installed product. Thus, H2 and H3 was supported. 4. Implications: The present study found the moderate effect by the product type of usage situation. Based on the findings the following managerial implications are asserted. First, it was found that information types are affect only the attitude toward the shopping mall. The meaning of this finding is that VR effects are not enough to understand the product itself. Therefore, we must consider when and how to use this VR tools. Second, it was found that there exist the interaction effects on the information usefulness, overall product quality and purchase intention. This finding suggests that consideration of usage situation helps consumer's understanding of product and promotes their purchase intention. In conclusion, not only product attributes but also product usage situations must be fully considered by the online retailers when they want to meet the needs of consumers.

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  • Development of New Device for the Rapid Measurement of the freshness of Wet Fish by Using Micro Computer (마이크로 컴퓨터를 이용한 어육의 신선도 측정장치의 개발)

    • CHO Young-Je;LEE Nam-Geoul;KIM Sang-Bong;CHOI Young-Joon;LEE Keun-Woo;KIM Geon-Bae
      • Korean Journal of Fisheries and Aquatic Sciences
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      • v.28 no.3
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      • pp.253-262
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      • 1995
    • To develop a device for measuring fish freshness which could be move accurate and reliable than used freshness measuring systems. A new device based on digital circuit was designed using a microcomputer. The device was composed of a sensor part, 8096 microprocessor and a segment display. The effectiveness of device has been evaluated by the coefficient of correlation among the measured freshness stores such as electrical Q-value, K-value and amount of volatile basic nitrogen (VBN) of plaice, Paralichthys Olivaceus, during storage at $-3^{\circ}C,\;0^{\circ}C,\;5^{\circ}C,\;10^{\circ}C,\;and\;25^{\circ}C$. Q-values measured by a new device were more closely correlated with K-value (r=-0.978-\;-0.962,\;p<0.05) and VBN (r=-0.888-\;-0.988,\;p<0.05) in case of plaice meat. If more data would achieve using various fishes, this new designed device could be a valuable kit in fish market by its compact portability.

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    Environmental Characteristics and Catch Fluctuations of Set Net Ground in the Coastal Water of Hanlim in Cheju Island I. Properties of Temperature and Salinity (제주도 한림 연안 정치망어장의 환경특성과 어획량변동에 관한 연구 I. 수온 및 염분특성)

    • KIM Jun-Teck;JEONG Dong-Gun;RHO Hong-Kil
      • Korean Journal of Fisheries and Aquatic Sciences
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      • v.31 no.6
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      • pp.859-868
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      • 1998
    • In order to investigate the relation between the marine environmental characteristics and the change of the catch in set net, the marine environment properties were analyzed by temperature and salinity observed in the western coastal area of Cheju Island from 1995 to 1996 and the results are as follows 1) Main axis of Tsushima Current appeared in the western coastal area of Cheju Island was off 2$\~$3 miles from November to May. Therefore the waters of high temperature over $14^{\circ}C$ and high salinity from $34.40\%_{\circ}$ to $34.60\%_{\circ}$ were distributed homogeneously from surface to bottom in this time. But China Coastal Waters of low salinity appeared in the Cheju Strait from June to October, surface waters became of high temperature and low salinity, and middle and bottom waters became of the temperature from 11 to $14^{\circ}C$ and the salinity over $33.50\%_{\circ}$ and then vertically sharp thermocline and halocline are formed in the western coastal area of Cheju Island. In summer, the water temperature and salinity of the surface waters in wstern coastal area of Cheju Island were lower and higher respectively than that in middle area of the Cheju Strait and the temperature and salinity of the bottom waters in this area were higher and lower, respectively than that in middle area of the Cheju Strait. Such a distribution shows a tidal front in this coastal area. On the whole year, surface temperature and salinity were from 14 to $23^{\circ}C$ and from 30.60 to $34.60\%_{\circ}$, respectively, and annual fluctuation range of temperature and salinity was within $9^{\circ}C$ and $4.00\%_{\circ}$, respectively, Thus, annual fluctuation range in this area is much narrower than that in the Cheju Strait. In bottom water, temperature ranges from 14 to $20^{\circ}C$ through the year. Thus, the fluctuation range of temperature is narrow. The low temperature of from $11^{\circ}C$ to $13^{\circ}C$ appeared in the west enterance of Cheju Strait was not shown in this coastal area. 2) The salinity of bottom water was from $33.60\%_{\circ}$ to $34.40\%_{\circ}$ in 1995, while low salinity wale. below $32.00\%_{\circ}$ appeared all depth from June in 1996. Thus, the variation of hydrographic conditions in this area is narrow in winter, and wide in summer due to the influence of China Coastal Waters. 3) In summer, surface cold water, local eddy and fronts of temperature and salinity were showed within 2 mile from the west coast of the Cheju Island due to vertical mixing by tidal current. Especially, temperature and salinity of bottom water are changed with the change of depth around Biyang-Do. Thus, the front of temperature and salinity appeared clearly between shallow area with the depth of under 10 m and deep area with of the depth of more than 50m. Surface water in outside area where high temperature and low salinity water appear intrudes between Worlreong-Ri and Geumreung-Ri. Thus, the front of temperature and salinity was made along the line that connects from this coast to Biyang-Do, The temperature of the bottom water is $2^{\circ}C$ to $4^{\circ}C$ lower than that of the surface water and its salinity is $0.02\%_{\circ}$ to $0.08\%_{\circ}$ higher than that of the surface water even in shallow area.

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    Lead Concentrations of Pigeon's Tissue as Indicator of Lead pollution in Air and Soil (대기 및 토양 오염의 지표로서 비둘기 조직의 연농도)

    • Byun, Yung-Woo;Hwang, Tae-Yoon;Lee, Jung-Jeung;Kim, Chang-Yoon;Chung, Jong-Hak
      • Journal of Preventive Medicine and Public Health
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      • v.29 no.1 s.52
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      • pp.15-26
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      • 1996
    • It has been studied that a variety of fauna and flora are sensitive biological indicators which reflect the severity of regional pollution of heavy metals, but in the center of part of Taegu City the controversial issue of lead poisoning attributable to the atmosphere which contains an increased concentrations of lead has been raised recently, it is usually hard to find suitable plants or animal in the areas with heavy traffic. Pigeons are ubiquitous in and around Taegu City area, inhabiting even the most densely populated areas with heavy traffic. With its small body size, high metabolic turnover, and rather limited mobility, a pigeon, as a biological indicator is expected. This study was conducted to monitor lead pollution in the Taegu and Kyongju City in Korea. We measured the lead content of the various tissue of three groups of feral pigeon(Columba livia) and soil and atmospheric lead concentration. First group was obtained in heavy traffic area in Taegu City, the second group was obtained a park in Taegu City and the third group was obtained light traffic area in Kyongju City. The air and soil lead concentration of heavy traffic area in Taegu City was $0.11{\mu}g/m^3,\;4.96{\mu}g/g$, that of park in Taegu City was $0.05{\mu}g/m^3,\;2.65{\mu}g/g$ and that of light traffic area in Kyongju City was $0.03{\mu}g/m^3,\;0.01{\mu}g/g$. The lead content of lung, blood, kidney, femur and liver of feral pigeons in heavy traffic area in Taegu City was significantly higher than pigeons obtained in a park in Taegu City and low traffic density area in Kyongju City(p<0.01). But stomach lead content of three group did not reflect a significant difference. In this study positive correlation was found between atmospheric lead concentrations and the concentration of lead in the pigeon's lung(r=0.5040, p<0.001), blood(r=0.3322, p<0.01), kidney(r=0.4824, p<0.001), femur(r=0.7214, p<0.001) and liver(r=0.4836, p<0.01). We can also found positive correlation between soil lead concentrations and the concentration of lead in the pigeon's femur(r=0.4850, p<0.001), kidney(r=0.4850, p<0.001) and liver(r=0.4386, p<0.01). In the pigeon's tissue there were significant correlations between concentration of lead in the blood and kidney(r=4818, p<0.001), femur(r=0.6157, p<0.001) and liver(r=0.3889, p<0.001). In conclusion, at the heavy traffic area in Taegu City, lead concentrations found in the atmosphere and soil are reflected in the lead concentrations of different tissue of urban pigeons. It is suggested that the tissue of pigeons can be good biological indicators of environmental lead pollution.

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    Henoch-$Sch{\ddot{o}}nlein$ Nephritis in Children (소아 Henoch-$Sch{\ddot{o}}nlein$ 신염의 추적 관찰)

    • Jang, Hee-Suk;Hong, In-Hee;Go, Cheol-Woo;Koo, Ja-Hun;Kwak, Jung-Sik
      • Childhood Kidney Diseases
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      • v.4 no.2
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      • pp.120-126
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      • 2000
    • Purpose : This retrospective study has been undertaken to find out the clinical outcome of children with HS nephntis and its relationship with initial clinical presentation and/or renal pathologic finding. Patients and methods : Study population consisted of 59 children with HS nephritis who have been admitted to the Pediatric department of Kyungpook University Hospital from 1987 to 1999, and biopsy was done with indications of heavy proteinuria (> 1 g/m2/day) lasting over 1 month, nephrotic syndrome, and persistent hematuria and/or proteinuria over 1 year. Patients were divided clinically into 3 groups ; isolated hematuria, hematuria with proteinuria and heavy proteinuria (including nephrotic syndrome). Biopsy findings ore graded from I-V according to International Study of Kidney Disease in Children (ISKDC). Results : Mean age of presentation was $8.1{\pm}3.0$ years and slight male preponderance m noted (33 boys md 26 girls). Histopathologic grading showed Grade I ; 2, Grade II ; 44, and Grade III ; 13 cases. Clinical outcome at the follow-up period of 1-2 year (49 cases) and 3-4 years (30 cases) shooed normal urinalysis in 75 (30.6$\%$) and 18 cases (60.0$\%$), persistent isolated hematuria in 20 (40.8$\%$) and 2 cases (6.7$\%$), hematuria with proteinuria in 11 (22.5$\%$) and 8 cases (26.6$\%$), and persistent heavy proteinuria in 3 (6.1$\%$) and 2 cases (6.7$\%$) respectively. Clinical outcome according to histopathologic grading showed the frequency of normalization of urinalysis being lower in Grade III compared to grade I or II. Clinical outcome according to initial clinical presentation showed no relationship to the normalization or urinalysis at follow-up periods. However, 15-20$\%$ of children with initial heavy proteinuria showed persistent heavy proteinuria (3 out of 20 cases at 1-2 years, and 2 out of 10 case at 3-4 years of follow-up periods). Conclusion : The majority of children with HS nephritis (histopathologic grade I, II, III) improved within 3-4 years and persistent heavy proteinuria was seen only in a kw of children with initial clinical presentation of heavy proteinuria.

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    Air Cavity Effects on the Absorbed Dose for 4-, 6- and 10-MV X-ray Beams : Larynx Model (4-, 6-, 10-MV X-선원에서 공기동이 흡수선량에 미치는 효과 : 후두모형)

    • Kim Chang-Seon;Yang Dae-Sik;Kim Chul-Yong;Choi Myung-Sun
      • Radiation Oncology Journal
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      • v.15 no.4
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      • pp.393-402
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      • 1997
    • Purpose : When an x-ray beam of small field size is irradiated to target area containing an air cavity, such as larynx, the underdosing effect is observed in the region near the interfaces of air and soft tissue. With a larynx model, air cavity embedded in tissue-equivalent material, this study is intonded for examining Parameters, such as beam quality, field size, and cavity size, to affect the dose distribution near the air cavity. Materials and Methods : Three x-rar beams, 4-, 6- and 10-MV, were employed to Perform a measurement using a 2cm $(width){\times}L$ (length in cm, one side of x-ray field used 2cm (height) air cavity in the simulated larynx. A thin window parallel-plate chamber connected to an electrometer was used for a dosimetry system. A ratio of the dose at various distances from the cavity-tissue interface to the dose at the same points in a homogeneous Phantom (ebservedlexpected ratio, O/E) normalized buildup curves, and ratio of distal surface dose to dose at the maximum buildup depth were examined for various field sizes. Measurement for cavity size effect was performed by varying the height (Z) of the air cavity with the width kept constant for several field sizes. Results : No underdosing effect for 4-MV beam for fields larger than $5cm\times5cm$ was found For both 6- and 10-MV beams, the underdosing portion of the larynx at the distal surface was seen to occur for small fields, $4cm\times4cm\;and\;5cm\times5cm$. The underdosed tissue was increased in its volume with beam energy even for similar surface doses. The relative distal surface dose to maximum dose was changed to 0.99 from 0.95, 0.92, and 0.91 for 4-, 6-, and 10-MV, respectively, with increasing field size, $4cm\times4cm\;to\;8cm\times8cm$, For 6- and 10-MV beams, the dose at the surface of the cavity is measured less than the predicted by about two and three percent. respectively. but decrease was found for 4-MV beam for $5cm\times5cm$ field. For the $4cm\timesL\timesZ$ (height in cm). varying depth from 0.0 to 4.8cm, cavity, O/E> 1.0 was observed regardless of the cavity size for any field larger than about $8cm\times8cm$. Conclusion : The magnitude of underdosing depends on beam energy, field size. and cavity size for the larynx model. Based on the result of the study. caution must be used when a small field of a high quality x-ray beam is irradiated to regions including air cavities. and especially the region where the tumor extends to the surface. Low quality beam. such as. 4-MV x-ray, and larger fields can be used preferably to reduce the risk of underdosing, local failure. In the case of high quality beams such as 6- and 10-MV x-rays, however. an additional boost field is recommended to add for the compensation of the underdosing region when a typically used treatment field. $8cm\times8cm$, is employed.

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