• Title/Summary/Keyword: Laboratory Experiment

Search Result 2,588, Processing Time 0.044 seconds

The Validation of a Commercial Testosterone RIA Test Kits (Testosterone RIA 검사 kit 별 유효성 비교평가)

  • Ryu, Hwa-jin;Shin, Seon-yeong;Cho, Seong-uk
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.26 no.1
    • /
    • pp.38-41
    • /
    • 2022
  • Purpose Testosterone is a steroid hormone synthesized by the Leydig cells of the testes in men, and by the adrenal cortex and ovaries in women. Testosterone production is regulated by luteinzing hormone secreted by the anterior pituitary gland. In this experiment, the effectiveness of testosterone radioimmunoassay (RIA) kits produced by three companies was evaluated and compared in case the production of testosterone kits was stopped or supply problems occurred. Materials and Methods In October 2021, samples were collected from the patients (n=49) who requested the testosterone RIA test. The experiment was conducted by dividing the patient's sample into low concentration (1.0 ng/mL or less), medium concentration (2.0-4.0 ng/mL) and high concentration (6.0 ng/mL or more). The Testosterone RIA test compared and evaluated the validity of Company A kits used in this hospital and those of Company B and C used in other hospitals. The precision, sensitivity, recovery, linearity and correlation were evaluated for each kit. The testosterone RIA test was carried out in accordance with the insert kit manual for each manufacturer. Results As a result of measuring the precision of the intra assay, the Coefficient of Variation (CV) value of the company A kit was high at 11.4% only in the low concentration sample, and in the case of the company B and C kits, the CV value was less than 10% at low, medium, and high concentrations. In the inter-assay precision measurement, the CV value was less than 15% in both A and C kits, but in the case of the B kit, the CV value exceeded 15% at low and medium concentrations. Sensitivity was 0.13 ng/mL for company A, 0.01 ng/mL for company B, and 0.01 ng/mL for company C, and the linearity of all three kits showed excellent linearity. In the case of recovery rate, all of the A, B, and C company kits showed results that were out of 90-110%. In the case of correlation test, when compared with the company A kit currently use in here, the correlation coefficient (R2) value for the company B kit was 0.9508, and for the company C kit was 0.9352 Conclusion As a result, there was a slight difference in precision at the low concentration sample. The correlation test showed an excellent correlation coefficient. However, it was difficult to secure samples of various concentrations because there were not many tests of testosterone requested at this hospital. So, additional experiments should be carried out by acquiring samples of various concentrations on each laboratory later.

Study on Intestinal Viability and Optimum Feeding Method of Lactobacillus in Broiler Chickens (육계에 대한 유산균의 장내 생존성 및 적정 급여방법에 대한 연구)

  • Kim, Dong-Wook;Kim, Ji-Hyuk;Kang, Geun-Ho;Kang, Hwan-Ku;Lee, Sang-Jin;Lee, Won-Jun;Kim, Sang-Ho
    • Journal of Animal Science and Technology
    • /
    • v.50 no.6
    • /
    • pp.807-818
    • /
    • 2008
  • This study was conducted to prove the optimum feeding method of Lactobacillus in broiler chickens by investigating the intestinal viability of ingested Lactobacillus and the effect of feeding levels and frequency of Lactobacillus on growth performance in broiler chickens. In experiment 1, A total of one hundred, 5 weeks old male broiler chickens(Abor Acre) were fed Lactobacillus reuteri avibro2 expressed green fluorescent protein(GFP) at 104cfu/g diet to investigate the retention time of ingested Lactobacillus in the intestine for 1 day. The percentage of Lactobacillus expressed GFP in intestinal contents was 26% at 1 day after fed Lactobacillus expressed GFP. The percentage of Lactobacillus expressed GFP in intestinal contents was decreased in length of time. In experiment 2, A total of four hundred eighty, 1-d-old male broiler chicks(Abor Acre) were randomly divided into 4 groups with 4 replicates of 30 birds each to prove the optimum feeding level of Lactobacillus. The treatments were control(free antibiotics), Lactobacillus reuteri avibro2 5.0×10cfu/mL, 5.0×103cfu/mL, and 5.0×105cfu/mL. The final body weight and body wight gain of Lactobacillus reuteri avibro2 5.0×103cfu/mL were the highest in all groups(P<0.05). Feed conversion ratio was not significantly difference among the groups. The number of intestinal lactic acid bacteria in Lactobacillus treated groups tended to be improved or significantly increased as compared to that of control(P<0.05). Protein and fat digestibility in Lactobacillus 5.0×103cfu/mL and 5.0×105cfu/mL treated groups were significantly improved(P<0.05). No significant differences were observed on the availability of dry matter and crude ash in Lactobacillus treatments compared to those of control. In experiment 3, A total of six hundred 1-d-old male broiler chicks(Abor Acre) were randomly divided into 4 groups with 4 replicates of 30 birds each and were fed Lactobacillus reuteri avibro2 at intervals of 1, 2, 3, and 5 day for five weeks. Feeding level of Lactobacillus was 5.0×103cfu/mL The final body weight and body wight gain of Lactobacillus reuteri avibro2 5.0×103cfu/mL were the highest in all groups(P<0.05). The final body weight and body weight gain were significantly increased, when Lactobacillus was fed at intervals of 1 days, or 2 days. There were no significant differences in feed intake and feed conversion ratio among the all groups. The number of intestinal lactic acid bacteria in Lactobacillus treated groups tended to be improved or significantly increased as compared to that of control(P<0.05). No significant differences were observed on the number of coliform bacteria and Salmonella of ileum and cecum. Consequently, supplemental Lactobacillus influenced positive effects on the growth performance, nutrient availability and intestinal microflora. The optimum feeding level of Lactobacillus was 5.0×103cfu/mL, and the constant feeding of Lactobacillus was effective.

The Role of Control Transparency and Outcome Feedback on Security Protection in Online Banking (계좌 이용 과정과 결과의 투명성이 온라인 뱅킹 이용자의 보안 인식에 미치는 영향)

  • Lee, Un-Kon;Choi, Ji Eun;Lee, Ho Geun
    • Information Systems Review
    • /
    • v.14 no.3
    • /
    • pp.75-97
    • /
    • 2012
  • Fostering trusting belief in financial transactions is a challenging task in Internet banking services. Authenticated Certificate had been regarded as an effective method to guarantee the trusting belief for online transactions. However, previous research claimed that this method has some loopholes for such abusers as hackers, who intend to attack the financial accounts of innocent transactors in Internet. Two types of methods have been suggested as alternatives for securing user identification and activity in online financial services. Control transparency uses information over the transaction process to verify and to control the transactions. Outcome feedback, which refers to the specific information about exchange outcomes, provides information over final transaction results. By using these two methods, financial service providers can send signals to involved parties about the robustness of their security mechanisms. These two methods-control transparency and outcome feedback-have been widely used in the IS field to enhance the quality of IS services. In this research, we intend to verify that these two methods can also be used to reduce risks and to increase the security protections in online banking services. The purpose of this paper is to empirically test the effects of the control transparency and the outcome feedback on the risk perceptions in Internet banking services. Our assumption is that these two methods-control transparency and outcome feedback-can reduce perceived risks involved with online financial transactions, while increasing perceived trust over financial service providers. These changes in user attitudes can increase the level of user satisfactions, which may lead to the increased user loyalty as well as users' willingness to pay for the financial transactions. Previous research in IS suggested that the increased level of transparency on the process and the result of transactions can enhance the information quality and decision quality of IS users. Transparency helps IS users to acquire the information needed to control the transaction counterpart and thus to complete transaction successfully. It is also argued that transparency can reduce the perceived transaction risks in IS usage. Many IS researchers also argued that the trust can be generated by the institutional mechanisms. Trusting belief refers to the truster's belief for the trustee to have attributes for being beneficial to the truster. Institution-based trust plays an important role to enhance the probability of achieving a successful outcome. When a transactor regards the conditions crucial for the transaction success, he or she considers the condition providers as trustful, and thus eventually trust the others involved with such condition providers. In this process, transparency helps the transactor complete the transaction successfully. Through the investigation of these studies, we expect that the control transparency and outcome feedback can reduce the risk perception on transaction and enhance the trust with the service provider. Based on a theoretical framework of transparency and institution-based trust, we propose and test a research model by evaluating research hypotheses. We have conducted a laboratory experiment in order to validate our research model. Since the transparency artifact(control transparency and outcome feedback) is not yet adopted in online banking services, the general survey method could not be employed to verify our research model. We collected data from 138 experiment subjects who had experiences with online banking services. PLS is used to analyze the experiment data. The measurement model confirms that our data set has appropriate convergent and discriminant validity. The results of testing the structural model indicate that control transparency significantly enhances the trust and significantly reduces the risk perception of online banking users. The result also suggested that the outcome feedback significantly enhances the trust of users. We have found that the reduced risk and the increased trust level significantly improve the level of service satisfaction. The increased satisfaction finally leads to the increased loyalty and willingness to pay for the financial services.

  • PDF

Studies on the Effects of Several Factors on Soil Erosion (토양침식(土壤侵蝕)에 작용(作用)하는 몇가지 요인(要因)의 영향(影響)에 관(關)한 연구(硏究))

  • Woo, Bo Myeong
    • Journal of Korean Society of Forest Science
    • /
    • v.29 no.1
    • /
    • pp.54-101
    • /
    • 1976
  • This study was conducted on the major factors affecting soil erosion and surface run-off. In order to investigate the processes and mechanisms of soil erosion on denuded forest-land in Korea, and to systematize the magnitudes of influences and interactions between individual factors, the five major factors adopted in these experiments are soil textures (coarse sand and clay loam), slope steepness ($10^{\circ}$, $20^{\circ}$, $30^{\circ}$ and $40^{\circ}$), rainfall intensities (50, 75 and 100mm/hr), slope mulching methods (bare, coarse straw-mat mulching, grass mulching and anti-erosion liquid mulching) and vegetation densities (sparse, moderate and dense). The processes and mechanisms of soil erosion, and the effects of mulchings on soil erosion as well as surface run-off rates were studied algebraically with four parts of laboratory experiments under the simulated rainfall and another part of field experiment under the natural rainfall. The results in this study are summarized as follows: 1. Experiment factors and surface run-off rates The surface run-off rates under the natural rainfall were resulted about 24.7~28.7% from the bare slopes, about 14.0~16.4% from the straw-mat mulched slopes, about 7.9~9.1% from the liquid mulched slopes, and about 5.6~7.2% from the grass mulched slopes respectively. The surface run-off rates under the simulated rainfall differed greatly according to the rainfall intensity and the mulching method. 2. Magnitudes of influences and interactions of the individual factor on the surface run-off rates. The experimental analyses on the major factors(soils, slopes, rainfalls, mulchings and vegetations) affecting the rates of surface run-off, show that the mean differences of surface run-off rate are significant at 5% level between the soil texture factors, among the slope steepness factors, among the rainfall intensity factors, among the mulching method factors, and among the vegetation density factors respectively. The interactions among the individual factor have a great influence(significant at 1% level) upon the rate of surface run-off, except for the interactions of the factors between soils and slopes; between slopes and vegetations; among soils, slopes and rainfalls; and among soils, slopes and mulchings respectively. On the bare slopes under the simulated rainfall, the magnitude of influences of three factors(soils, slopes and rainfalls) affecting the rate of surface run-off is in the order of the factor of rainfalls, soils and slopes. The magnitude of influences of three factors (soils, rainfalls and mulchings) affecting the rate of surface run-off, on the mulched slopes under the simulated rainfall is in the order of the factor of mulchings, rainfalls and soils and that of influences of the factor of soils, slopes and mulchings is in the order of the factor of mulchings, soils and slopes. On the vegetation growing slopes under the simulated rainfall, the magnitude of influences of three factors (soils, slopes and vegetations) affecting the rate of surface run-off is in the order of the factor of vegetations, soils and slopes. In the same condition of treatments on the field experiment under the natural rainfall, the order of magnitude of influences affecting the rate of surface run-off is the factor of mulchings, soils and slopes. 3. Experiment factors and soil losses The soil losses of the experiment plots differed according to the factors of soil texture, slope steepness, rainfall intensity and mulching method. The soil losses from the coarse soil were increased about 1.1~1.3 times as compared with that of fine soil under the natural rainfall, while the soil losses from the fine soil were increased about 1.2~1.3 times compared with that of coarse soil under the simulated rainfall. The equation of $E=aS^b$ (a, b are constant) between the slope steepness (log S) and soil losses (log E) under the simulated rainfall were developed. The equation of $E=aI^b$ (a, b are constant) between the rainfall intensity (log I) and soil losses (log E) were developed, and b values have a decreasing tendency according to the increase of the slope steepness and rainfall intensity. The soil losses under the natural rainfall were appeared about 38~41% from the coarse straw-mat mulched slopes, about 20~22% from the liquid mulched slopes, about 14~15% from the grass mulched slopes as compared with that of the bare slopes respectively. The soil loss from the vegetation plots showed about 7.1~16.4 times from the sparse plot, about 10.0~17.9 times from the moderate plot and about 11.1~28.1 times from the dense plot as compared with that of the bare slopes. 4. Magnitudes of influences and interactions of the individual factor on the soil erosion. The experimental analyses on the major factors(soils, slopes, rainfalls, mulchings and vegetations) affecting the soil erosion, show that the mean differences of soil losses are highly significant between the soil texture factors, among the slope steepness factors, among the rainfall intensity factors, among the mulching method factors and among the vegetation density factors respectively. The interactions among the individual factor have mostly great influences upon the soil erosion. The magnitude of influences of three factors (soils, slopes and rainfalls) affecting the soil erosion on the bare slopes under the simulated rainfall is in order of the factor of rainfalls, soils and slopes. On the mulched slopes under the simulated rainfall, the magnitude order of influences of three factors(soils, rainfalls and mulchings) affecting the soil erosion is the factor of mulchings, rainfalls and soils, and the order of influences of factor of soils, slopes and mulchings is the factor of mulchings, soils and slopes. On the vegetation growing slopes under the simulated rainfall, the magnitude of influences of three factors (soils, slopes and vegetations) affecting the soil erosion is in the order of the factor of slopes. vegetations and soils. In the same condition of treatments on the field experiment under the natural rainfall, the order of magnitude of influences of three factors (soils, slopes and mulchings) affecting the soil erosion is the factor of mulchings, of slopes and of soils.

  • PDF

Fly Ash Application Effects on CH4 and CO2 Emission in an Incubation Experiment with a Paddy Soil (항온 배양 논토양 조건에서 비산재 처리에 따른 CH4와 CO2 방출 특성)

  • Lim, Sang-Sun;Choi, Woo-Jung;Kim, Han-Yong;Jung, Jae-Woon;Yoon, Kwang-Sik
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.45 no.5
    • /
    • pp.853-860
    • /
    • 2012
  • To estimate potential use of fly ash in reducing $CH_4$ and $CO_2$ emission from soil, $CH_4$ and $CO_2$ fluxes from a paddy soil mixed with fly ash at different rate (w/w; 0, 5, and 10%) in the presence and absence of fertilizer N ($(NH_4)_2SO_4$) addition were investigated in a laboratory incubation for 60 days under changing water regime from wetting to drying via transition. The mean $CH_4$ flux during the entire incubation period ranged from 0.59 to $1.68mg\;CH_4\;m^{-2}day^{-1}$ with a lower rate in the soil treated with N fertilizer due to suppression of $CH_4$ production by $SO_4^{2-}$ that acts as an electron acceptor, leading to decreases in electron availability for methanogen. Fly ash application reduced $CH_4$ flux by 37.5 and 33.0% in soils without and with N addition, respectively, probably due to retardation of $CH_4$ diffusion through soil pores by addition of fine-textured fly ash. In addition, as fly ash has a potential for $CO_2$ removal via carbonation (formation of carbonate precipitates) that decreases $CO_2$ availability that is a substrate for $CO_2$ reduction reaction (one of $CH_4$ generation pathways) is likely to be another mechanisms of $CH_4$ flux reduction by fly ash. Meanwhile, the mean $CO_2$ flux during the entire incubation period was between 0.64 and $0.90g\;CO_2\;m^{-2}day^{-1}$, and that of N treated soil was lower than that without N addition. Because N addition is likely to increase soil respiration, it is not straightforward to explain the results. However, it may be possible that our experiment did not account for the substantial amount of $CO_2$ produced by heterotrophs that were activated by N addition in earlier period than the measurement was initiated. Fly ash application also lowered $CO_2$ flux by up to 20% in the soil mixed with fly ash at 10% through $CO_2$ removal by the carbonation. At the whole picture, fly ash application at 10% decreased global warming potential of emitted $CH_4$ and $CO_2$ by about 20%. Therefore, our results suggest that fly ash application can be a soil management practice to reduce green house gas emission from paddy soils. Further studies under field conditions with rice cultivation are necessary to verify our findings.

Arsenic Removal Mechanism of the Residual Slag Generated after the Mineral Carbonation Process in Aqueous System (광물탄산화 공정 이후 발생하는 잔사슬래그의 수계 내 비소 제거 기작)

  • Kim, Kyeongtae;Latief, Ilham Abdul;Kim, Danu;Kim, Seonhee;Lee, Minhee
    • Economic and Environmental Geology
    • /
    • v.55 no.4
    • /
    • pp.377-388
    • /
    • 2022
  • Laboratory-scale experiments were performed to identify the As removal mechanism of the residual slag generated after the mineral carbonation process. The residual slags were manufactured from the steelmaking slag (blast oxygen furnace slag: BOF) through direct and indirect carbonation process. RDBOF (residual BOF after the direct carbonation) and RIBOF (residual BOF after the indirect carbonation) showed different physicochemical-structural characteristics compared with raw BOF such as chemical-mineralogical properties, the pH level of leachate and forming micropores on the surface of the slag. In batch experiment, 0.1 g of residual slag was added to 10 mL of As-solution (initial concentration: 203.6 mg/L) titrated at various pH levels. The RDBOF showed 99.3% of As removal efficiency at initial pH 1, while it sharply decreased with the increase of initial pH. As the initial pH of solution decreased, the dissolution of carbonate minerals covering the surface was accelerated, increasing the exposed area of Fe-oxide and promoting the adsorption of As-oxyanions on the RDBOF surface. Whereas, the As removal efficiency of RIBOF increased with the increase of initial pH levels, and it reached up to 70% at initial pH 10. Considering the PZC (point of zero charge) of the RIBOF (pH 4.5), it was hardly expected that the electrical adsorption of As-oxyanion on surface of the RIBOF at initial pH of 4-10. Nevertheless it was observed that As-oxyanion was linked to the Fe-oxide on the RIBOF surface by the cation bridge effect of divalent cations such as Ca2+, Mn2+, and Fe2+. The surface of RIBOF became stronger negatively charged, the cation bridge effect was more strictly enforced, and more As can be fixed on the RIBOF surface. However, the Ca-products start to precipitate on the surface at pH 10-11 or higher and they even prevent the surface adsorption of As-oxyanion by Fe-oxide. The TCLP test was performed to evaluate the stability of As fixed on the surface of the residual slag after the batch experiment. Results supported that RDBOF and RIBOF firmly fixed As over the wide pH levels, by considering their As desorption rate of less than 2%. From the results of this study, it was proved that both residual slags can be used as an eco-friendly and low-cost As remover with high As removal efficiency and high stability and they also overcome the pH increase in solution, which is the disadvantage of existing steelmaking slag as an As remover.

Evaluation of HalcyonTM Fast kV CBCT effectiveness in radiation therapy in cervical cancer patients of childbearing age who performed ovarian transposition (난소전위술을 시행한 가임기 여성의 자궁경부암 방사선치료 시 난소선량 감소를 위한 HalcyonTM Fast kV CBCT의 유용성 평가 : Phantom study)

  • Lee Sung Jae;Shin Chung Hun;Choi So Young;Lee Dong Hyeong;Yoo Soon Mi;Song Heung Gwon;Yoon In Ha
    • The Journal of Korean Society for Radiation Therapy
    • /
    • v.34
    • /
    • pp.73-82
    • /
    • 2022
  • Purpose: The purpose of this study is to evaluate the effectiveness of reducing the absorbed dose to the ovaries and the quality of the CBCT image when using the HalcyonTM Fast kV CBCT of cervical cancer patients of child-bearing age who performed ovarian transposition Materials and Methods : Contouring of the cervix and ovaries required for measurement was performed on the computed tomography images of the human phantom (Alderson Rando Phantom, USA), and three Optically Stimulated Luminescence Dosimeter(OSLD) were attached to the selected organ cross-section, respectively. In order to measure the absorbed dose to the cervix and ovaries in the TruebeamTM pelvis mode (Hereinafter referred to as TP), The HalcyonTM Pelvis mode (Hereinafter referred to as HP) and The HalcyonTM Pelvis Fast mode (Hereinafter referred to as HPF), An image was taken with a scan range of 17.5 cm and also taken an image that reduced the Scan range to 12.5cm. A total of 10 cumulative doses were summed, It was replaced with a value of 23 Fx, the number of cervical cancer treatments, and compared In additon, uniformity, low contrast visibility, spatial resolution, and geometric distortion were compared and analyzed using Catphan 504 phantom to compare CBCT image quality between equipment. Each factor was repeatedly measured three times, and the average value was obtained by analysing with the Doselab (Mobius Medical Systems, LP. Versions: 6.8) program. Results: As a result of measuring absorbed dose by CBCT with OSLD, TP and HP did not obtain significant results under the same conditions. The mode showing the greatest reduction value was HPF versus TP. In HPF, the absorbed dose was reduced by 39.8% in the cervix and 19.8% in the ovary compared to the TP in the scan range of 17.5 cm. the scan range was reduced to 12.5 cm, absorbed dose was reduced by 34.2% in the cervix and 50.5% in the ovary. In addition, result of evaluating the quality of the image used in the above experiment, it complied with the equipment manufacturer's standards with Geometric Distortion within 1mm (SBRT standard), Uniformity HU, LCV within 2.0%, Spatial Resolution more than 3 lp/mm. Conclusion: According to the results of this experiment, HalcyonTM can select more various conditions than TruebeamTM in treatment of fertility woman who have undergone ovarian Transposition , because it is important to reduce the radiation dose by CBCT during radiation therapy. So finally we recommend HalcyonTM Fast kV CBCT which maintains image quality even at low mAs. However, it is consider that the additional exposure to low doses can be reduced by controlling the imaging range for patients who have undergone ovarian transposition in other treatment machines.

Studies on the Life History of Bacciger harengulae (Bacciger harengulae의 생활사에 관한 연구)

  • KIM Young-Gill;CHUN Seh-Kyu
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.17 no.5
    • /
    • pp.449-470
    • /
    • 1984
  • The cercaria of Bacciger herengulae which is parasitized on the gonad of Solen strictus was investigated in order to reveal its entire life history. The area covered for the study was in the vicinity sea of Naechodo, the estuary of the Kum river in the western coast of Korea during the period of 1980-1983. Morphology and development as well as infection rates of sporocyst and cercaria within Solen strictus were examined. For accomplishing the objectives of this study, an artificial infection experiment and some investigations on the second intermediate host, the final host and the growing stages were also studied in both laboratory and natural habitat of Solen strictus. According to the study, it was revealed that the first intermediate hosts were Meretrix lusoria, Solen strictus, Tapes japonica and Laternula limicola, the second intermediate host was Palaemon (Exopalaemon) carinicauda and the final hosts were Konosirus punctatus and Harengula zunasi. A mature sporocyst which was found in the gonad of Solen strictus was $4.0-4.3{\times}0.2-0.21\;mm$ insize, and the cercaia with 27 pairs of setae, each seta consisting of 6 tufts, was $270{\times}147{\mu}m$ in body size and $550{\times}52{\mu}m$ in tail size. Oral sucker($52{\times}42{\mu}m$), pharynx, vental sucker and two testese were obviously seen within the cercaria. The excretory vesicles of cercaria were in V-shape and the flame cell were formula was expressed as 2[(3+3)+(3+3)]=24. The infection of cercaria in the first intermediate host, Solen strictus, was found throughout the year regardlless of the water temperature, and its mean infection rate was $9.67\%$ during the study period. The infection rate fluctuated with temperature, the highest being $28.0\%\;at\;28.0^{\circ}C$ water temperature in July and the lowest $2.4\%\;at\;19.5^{\circ}C$ in October, and it increased in proportion to the shell length on the host. But cercaria was not detected at below 4.0 cm in size of the host. Mature cercariae were found 6 months from May to October when water temperature was above $19.5^{\circ}C$. On the other hand, when water temperature was below $19.5^{\circ}C$, only immature cercariae and sporocysts were found. The cercariae were active for 35 hours and survived for 71 hours at $20^{\circ}C$, and 29 and 34 hours at $25^{\circ}C$ respectively, whereas the cercariae were inactive at less than $20^{\circ}C$ in water temperature. Cercaria, from Solen strictus, approached shrimp of 1-3 cm in body length as its second host. Then, it began to intrude in to the muscle of shrimp after 2-3 hours. The infected cercaria formed cyst after 7-8 hours, and became mature metacercaria. $420{\times}310{\mu}m$ in size, 15 days afer infection. The infection rate of metaceria to shrimp in the laboratory was highest, at $25^{\circ}C$ being $61\%$ and at $20^{\circ}C\;17%$. The infection rate of metacearia in shrimp was highest in the first abdominal segment, followed by cephalothorax, the second, and fifth abdominal segments, and in that order. Also, the infection rate of metacercaria in wild shrimp was high $9.6-11.1\%$ at $26.5^{\circ}C$ in June, and low $1.56-2.5\%$ at $28-29.5^{\circ}C$ from July to August. The infected shrimp with metacercaria was experimentally fed to Konosirus punctatus in the laboratory in order to know its final host. The metacercaria developed into the adult worm, $440-520{\times}310-360{\mu}m$ in size, within the intestine of Konosirus punctatus 20 days after infection. The adult worm was oval shape and $20-24{\times}11-20{\mu}m$ in size. The infection rate of adult worm to Konosirus punctatus and Harengula zunasi ranged 87.3 to $100\%$, the mean being $95.2\%$, regardless of the body length of their hosts. The infection rate was $100\%$ in June and July, but it decreased in September and October. The size and body structure of the trematode observed during the present study were well agreed with those ievestigated by Yamaguti(1938), thus, it may be concluded that the adult worm it identified as Bacciger harengulae.

  • PDF

Evaluation of Potentially Available Soil Nitrogen by Using Buffer Phosphote Solution of pH7 (답토양(畓土壤)의 인산완형액(燐酸緩衡液)에 의(依)한 지력질소(地力窒素) 평가(評價)에 관(關)한 연구(硏究))

  • Ahn, Sang-Bae
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.19 no.4
    • /
    • pp.327-332
    • /
    • 1986
  • Laboratory experiments were conducted to estimate extractable nitrogen by buffer phosphate solution of pH 7. A series of experiment soils were a) Sandy soil applied with compost, lime, and Wallastonite every years for 32 years. b) Sandy soils with and without waterlogging for 70 days before transplanting. c) Normal soils produced high and common yields. The results were summarized as follows: 1. Extractable organic nitrogen by pH 7 phosphate buffer solution was increased in order of NPK + compost > NPK > NPK + compost + lime + Wollast-onite > NPK + compost + lime > NPK + wollastonite > no fertilizer plot. 2. Extractable organic nitrogens at plots of NPK and NPK + compost were decreased as the growth stage processed regardless of tretments. 3. In case of normal soils having high and common yields the content of total N, organic matter and $NH_4-N$ were increased in high productive soil, while, only $NO_3-N$ content was increased in common productive soil. Especially, there was a highly positive correlation between extractable total nitrogen and $NH_4-N$ content submerged for 4 weeks under incubated condition. 4. Organic nitrogen content of soil was increased on the condition of non-waterlogging, however, nitrogen uptake by rice plant was increased in waterlogged paddy. 5. The content of extractable total nitrogen increased in the order of normal soil, sandy soil, unmatured soil, saline soil, and estimation of optimum nitrogen rates by extracted organic nitrogen was in order of saline soil, unmatured soil, sandy soil, normal soil.

  • PDF

A Study on the Development of Curriculum for the Department of Fisheries Processing in Fisheries Junior College (전문대학(專門大學) 수산가공과(水產加工科) 교육과정(敎育科程) 개선(改善)에 관한 연구(硏究))

  • Seong, Dae-Hwan;Choi, Jong-Duck;Kim, Jeong-Gyun
    • Journal of Fisheries and Marine Sciences Education
    • /
    • v.2 no.1
    • /
    • pp.15-28
    • /
    • 1989
  • The aim of this study is to improve the curriculum for the fisheries processing department in fisheries junior college in Korea. For this study, questionaries to alumani and students of the fisheries processing department of Tong-Yeong Fisheries Junior College are made and meeting materials of professors concerned and some leading managers of food processing company. In addition, curricula of the department food processing in two year or four year colleges both domestic and foreign are refered. The results obtained can be shown as follows ; 1. Subjects of the standard laboratory work designated by the Ministry of Education and required at the practical techique examination for the food precessing technitian certificates were chosen to student compulsorily, and the other subjects necessary to acquistion of the techniques were opened in this course electively. 2. The food processing departments in nationwide twenty-three junior college open seventy-eight major subject courses. Among those subjects, we choose the subjects only related to fisheries processing ones to put stress on the features of fisheries processing department. 3. The selected courses in improved curricula of this work are total 119 credits spending 142 class-hour per weeks. Detailed curricula are as follows ; liberal arts are consist of 13 subjects-24 credits, essential major subjects 12 subjects-32 credits, elective subjects 24 subject-56 credits and interdisciplinary subjects 2 subjects-5 credits. 4. The linking system of industrial-educational co-operation have to be established to fulfil the field practice, and legal basis should be made to support these educational circumstances. 5. To make sure a live education in junior college, present education terms should be extended more than 1 year, and improved textbook, method of experiment, practice and evaluation continuously.

  • PDF