• The Korean Journal of Pesticide Science
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• v.17 no.1
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• pp.33-40
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• 2013

Pyrifluquinazon is known to act as a feeding inhibitor in several insect species. In this study, we investigated the effect of pyrifluquinazon on the whiteflies, Trialeurodes vaporariorum and Bemisia tabaci. Pyrifluquinazon showed high insecticidal activity (> 90%) against adult T. vaporariorum and B. tabaci at 12.5 ppm to 50 ppm. However, there was no effect on eggs and nymphs of both species. Pyrifluquinazon showed low insecticidal activity in root and foliar uptake. Control efficacy of pyrifluquinazon was above 90% at 5 days after treatment. In order to investigate the behavioral response of the whiteflies initiated by application of pyrifluquinazon, we tested the contact toxicity and ingestion toxicity. After 1 h of contact, whitefly drop, wing convulsion, and paralysis were observed. Similar phenomenon of whitefly population was observed in test of ingestion toxicity after 3 h. In the choice test, pyrifluquinazon showed repellent activity against both species. These results suggest that pyrifluquinazon cause behavioral disorder rather than direct inhibition of feeding.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.2
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• pp.144-151
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• 1991

Composition and unsaturation ratio of fatty acids composing phospholipid which is the main constituent of biological membranes are known to be related to the response of plant to cold stress. In order to investigate a relationship between fatty acid unsaturation ratio of phospholipid and the range of cold tolerance of rice cultivars obtained in the field experiment, the lipid from the leaves of 32 rice cultivars were isolated and the fatty acid composition of phospholipid was determined by gas chromatography. In this experiment, composition and unsaturation ratio of fatty acids composing phopholipid on rice plants grown under natural condition and treated with chilling temperature were compared with the cold tolerance in the field for rice cultivars. The results obtained were summarized as follows ; 1. The phospholipids isolated from the leaves of 32 rice cultivars both grown under natural condition and chilling treatment contained palmitic, linoleic and linolenic acid as major components and palmitoleic, stearic and oleic acid as minor components. 2. The content of palmitic acid, a saturated fatty acid, was reduced in rice seedlings subjected to chilling treatment for 3 days at $15^{\circ}C$, and contents of linoleic and linolenic acid, unsaturated fatty acids, were increased. 3. The unsaturation ratio of fatty acid was increased by chilling treatment, and was high in cold-tolerant cultivars but low in cold-susceptible cultivars and the results were correlated with the range of cold tolerance investigated in the field. 4. The content of palmitic acids among fatty acids composing phospholipid was reduced and that of linolenic acid was increased by hardening treatment. 5. The unsaturation ratio of fatty acid was increased 18~24% by hardening treatment compared to control.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.793-802
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• 1998

Salmonellosis caused by a number of serotypes of Salmonella is an infectious, acute or chronic, zoonotic disease and characterized by enteritis and diarrhea, septicemia in animal. In these studies we investigated the prevalent serotypes of Salmonella causing animal salmonellosis in Korea and the 71 strains of Salmonella spp. were isolated from materials such as mesenteric lymph nodes, fecal samples from slaughtered animal. With the identification test results, the most prevalent serotypes were, in order, S stanley 31 strains (43.7%), S typhimurium 19 strains (26.8%) and S montevideo 11 strains (15.5%), respectively. And we could establish the method for detection of antibodies to broad variety of Salmonella serotypes. Lipopolysaccharide(LPS) antigen extracted from Salmonella was more sensitive and specific than outer membrane protein antigen from that for detection of Salmonella antibody by using an indirect ELISA. The optimal concentration of antigen was 100ng/ml of LPS, the dilutions of conjugate and serum were 1 : 1,000~2,000 and 1 : 200~400, respectively. The mix LPS-ELISA which was used by mixing LPS from S typhimurium (group B), S choleraesuis (group C) and S enteritidis (group D) were more rapid and effective than that used LPS from individual strain for detection of Salmonella serogroup O4, O7 and O9 antibody at the same time. We could obtain the high values of optical density ($0.73{\pm}0.32$) by mix LPS-ELISA on the farm which had occurred salmonellosis, but very low values of $0.17{\pm}0.06$ on the negative farm of salmonellosis. So, the mix LPS-ELISA may be used to monitor the serological surveillance for the presence of infection with a number of serotypes of Salmonella and would be useful for prevention and control of salmonellosis in animal.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.2
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• pp.266-277
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• 2014

Somatic cell nuclear transfer (SCNT) has generally demonstrated that a differentiated cell can convert into a undifferentiated or pluripotent state. In the SCNT experiment, nuclear reprogramming is induced by exposure of introduced donor nuclei to the recipient cytoplasm of matured oocytes. However, because the efficiency of SCNT still remains low, a combination of SCNT technique with the ex-ovo method may improve the normal development of SCNT embryos. Here we hypothesized that treatment of somatic cells with extracts prepared from the germinal vesicle (GV) stage Siberian sturgeon oocytes prior to their use as nuclear donor for SCNT would improve in vitro development. A reversible permeability protocol with $4{\mu}g/mL$ of digitonin for 2 min at $4^{\circ}C$ in order to deliver Siberian sturgeon oocyte extract (SOE) to porcine fetal fibroblasts (PFFs) was carried out. As results, the intensity of H3K9ac staining in PFFs following treatment of SOE for 7 h at $18^{\circ}C$ was significantly increased but the intensity of H3K9me3 staining in PFFs was significantly decreased as compared with the control (p<0.05). Additionally, the level of histone acetylation in SCNT embryos at the zygote stage was significantly increased when reconstructed using SOE-treated cells (p<0.05), similar to that of IVF embryos at the zygote stage. The number of apoptotic cells was significantly decreased and pluripotency markers (Nanog, Oct4 and Sox2) were highly expressed in the blastocyst stage of SCNT embryos reconstructed using SOE-treated cells as nuclear donor (p<0.05). And there was observed a better development to the blastocyst stage in the SOE-treated group (p<0.05). Our results suggested that pre-treatment of cells with SOE could improve epigenetic reprogramming and the quality of porcine SCNT embryos.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.90-98
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• 2009

The aim of this study was to evaluate the effect of a milling by-product diet and two sugar cane diets on the local Creole pig breed (CR). A total of 48 CR pigs (24 females and 24 castrated males) were randomly assigned to four different groups of 12 animals. Pigs were allotted to one of 4 dietary treatments: fed with a control soya-bean meal-corn diet containing 19.1% crude protein (CP) and 15.4 MJ DE/kg (diet 1), with an experimental milling by-product diet (soya-bean meal and wheat by-products) containing 19.4% CP and 13.0 MJ DE/kg (diet 2), with ground cane stalks (GCS) or with fresh sugar cane juice (SCJ). Both GCS and SCJ were supplemented with soya-bean meal complement (400 g/d of a 48.7% CP and 16.1 MJ DE/kg diet) in order to obtain diets 3 and 4, respectively. Pigs were fed close to ad libitum level and had free access to water. All the pigs were slaughtered at 65 kg BW. Between 30 and 65 kg BW, growth performance was significantly (p<0.001) affected by dietary treatments: average daily BW gain was 657, 530, 546 and 200 g/d for diets 1, 2, 4, and 3, respectively. Average daily DM intake was 1.8, 1.9, 2.5 and 1.4 kg/d for diets 1, 2, 4, and 3, respectively. Fat cuts (backfat+leaf fat) and backfat thickness were significantly lower on diet 3 than for other treatments (127 vs. 192, 166 g/kg of left half-carcass weight and 24.6 vs. 39.0, 35.3 mm for diet 3 vs. diets 1 and 4, and diet 2, respectively; p<0.001). The dressing weight was significantly lower on diets 2 (82.7 vs. 84.0%; p<0.001). The entire empty digestive tract (DT) weight was higher on diet 2 (73.1 vs. 66.7 g/kg empty BW). However, stomach and large intestine were more developed on diet 3: 12.8 vs. 9.3 g/100 g empty DT (p<0.001) and 26.4 vs. 23.8 g/100 g empty DT (p<0.05), respectively. In conclusion, this study suggests the CR pig has the ability to reach rather good growth and carcass performance with a well-formulated sugar cane meal and/or with a milling by-product diet refined according to its low requirements.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.777-781
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• 2004

This paper presents an algorithm for multichannel slotted-ring topology medium access protocol (MAC) using in wavelength division multiplexing (WDM) networks. In multichannel ring, there are two main previously proposed architectures: Tunable Transmitter - Fixed Receiver (TTFR) and Fixed Transmitter - Tunable Receivers (FTTR). With TTFR, nodes can only receive packets on a fixed wavelength and can send packets on any wavelengths related to destination of packets. Disadvantage of this architecture is required as many wavelengths as there are nodes in the network. This is clearly a scalability limitation. In contrast, FTTR architecture has advantage that the number of nodes can be much larger than the number of wavelength. Source nodes send packet on a fixed channel (or wavelength) and destination nodes can received packets on any wavelength. If there are fewer wavelengths than there are nodes in the network, the nodes will also have to share all the wavelengths available for transmission. However the fixed wavelength approach of TTFR and FTTR bring low network utilization. Because source node with waiting data have to wait for an incoming empty slot on corresponding wavelength. Therefore this paper presents Tunable Transmitter - Tunable Receiver (TTTR) approach, in which the transmitting node can send a packet over any wavelengths and the receiving node can receive a packet from any wavelengths. Moreover, the self-similar distributed input traffic is used for evaluation of the performance of the proposed algorithm. The self-similar traffic performs better performance over long duration than short duration of the Poison distribution. In order to increase bandwidth efficiency, the Destination Stripping approach is used to mark the slot which has already reached the desired destination as an empty slot immediately at the destination node, so the slot does not need to go back to the source node to be marked as an empty slot as in the Source Stripping approach. MATLAB simulator is used to evaluate performance of FTTR, TTFR, and TTTR over 4 and 16 nodes ring network. From the simulation result, it is clear that the proposed algorithm overcomes higher network utilization and average throughput per node, and reduces the average queuing delay. With future works, mathematical analysis of those algorithms will be the main research topic.

• Journal of the Korean Chemical Society
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• v.42 no.3
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• pp.266-276
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• 1998

Cholesterol supersaturation in bile, which causes gallstone formation, is the result of low bile acid secretion or high cholesterol secretion. The quantitative analysis of cholesterol, bile acids and sterols which are precursors of cholesterol have been used to examine the changes in bile component. We described a simple, sensitive and reproducible method for simultaneous determination of cholesterol, five bile acids and seven sterols in human bile juices and gallstones by capillary column gas chromatography-mass spectrometry (GC/MS). Clinical samples were hydrolyzed by alcoholic KOH, extracted twice (pH 14 and 1) and derivatized to trimethylsilyl (TMS) ether with $MSTFA/NH_4I$ (N-methyl-N-trimethylsilyltrifluoroacetamide/ammonium iodide) mixture in order to be detected on the GC/MS. The good quality control data were obtained through within-a-day and day-to-day test (RSD values were 1.72-13.79, 0.68-14.10, respectively) and the recovery range of them was 73.56-96. 95 Using this method, biliary and gallstone compositions in the patients with intrahepatic stones were analyzed. The amounts and its relative distribution of cholesterol, bile acids and sterols showed different pattern in bile juices and gallstones.

• Membrane Journal
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• v.27 no.3
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• pp.248-254
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• 2017

In order to secure the reliability of pathogenic microorganisms such as Cryptosporidium and Giaridia, which are chlorophilic protozoans, membrane filtration systems have been widely used in water purification process. hese integrity tests are classified into direct and indirect methods. Based on the bubble point theory, the pressure-based test in the direct method is presented in the USEPA Guidance Manual with sensitivity to detect a minimum size of pathogenic microorganisms of $3{\mu}m$ or more. Indirect methods are widely used in that they are capable of continuous operation in on-line state, but there is a very low sensitivity of damage detection compared to the direct method, and there is a limit that can not specify the damage area, so it is necessary to improve this sensitivity. In this study, we compared the LRVDIT and UCL values according to the type of membrane defect, number of fiber breaks, and initial set pressure value through the Integrity Test by Pressure Decay Test (PDT).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.11
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• pp.2218-2229
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• 2015

Recently Wi-Fi Alliance defined Wi-Fi direct, which can communicate through a direct connection between the mobile device anytime, anywhere. In Wi-Fi direct, all devices are categorized by group of owner (GO) and client. Since portability is emphasized in Wi-Fi direct devices, it is essential to control the energy consumption of a device very efficiently. In order to avoid unnecessary power consumed by GO, Wi-Fi direct standard defines two power management schemes: Opportunistic power saving scheme and Notice Of Absence (NOA) scheme. But, these two schemes do not consider the traffic pattern, so we cannot expect high energy efficiency. In this paper, we suggest an algorithm to enhance the energy efficiency of Wi-Fi direct power saving, considering the characteristics of multimedia video traffic. Proposed algorithm utilizes the statistical distribution for the size of video frames and adjusts the length of awake interval dynamically. Also, considering the inter-dependency among video frames, the proposed algorithm assigns priorities to video frames and ensures that a video frame with high priority is transmitted with higher probability than other frames with low priority. Simulation results shows that the proposed method outperforms the traditional NOA in terms with average delay and energy efficiency.

• Journal of the Korea Concrete Institute
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• v.15 no.1
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• pp.134-142
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• 2003

Autogenous shrinkage, a significant contributor of early-age cracking of high strength concrete (HSC), must be avoided or minimized from an engineering point of view. Therefore, it is necessary to study how to reduce and to predict autogenous shrinkage with respect to tile control of early-age cracking. In this study, autogenous shrinkage of HSC with various water-binder ratio (W/B) ranging from 0.50 to 0.27 and fly ash content of 0, 10, 20, and 30% were investigated. Based on the test results, thereafter, a prediction model for autogenous shrinkage was proposed. Test results show that autogenous shrinkage increased and more rapidly developed with decreasing the W/B. Also, the higher fly ash contents, the smaller autogenous shrinkage. In particular, even if much autogenous shrinkage occurs at very early-ages, stress may not be developed while the stiffness of concrete is low. In order to consider the change of concrete stiffness, the transition time referred as stiffening threshold, was obtained by monitoring of ultrasonic pulse velocity evolution and considered in the autogenous shrinkage model. From a practical point of view, the proposed model can be effectively used to predict autogenous shrinkage and to estimate stress induced by autogenous shrinkage.