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Food and feeding activity of micronektonic fish, Gonostomatidae, from meso-and upper bathypelagic layers in the northeastern Atlantic (북동 대서양에서의 중심층 및 상부점심층산 앨퉁이과 어류 마이크로넥톤의 섭이양식)

  • 고유봉;쥴리안
    • 한국해양학회지
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    • v.21 no.2
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    • pp.85-91
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    • 1986
  • Diet and feeding patterns of 10 species of gonostomatid fish in the Rockall Trough and Porcupine Seabight, northeastern Atlantic, were investigated as a part of studies analyzing the meso-and upper bathypelagic micronektonic fish communities in these two areas. Copepods were the major food organisms, composing more than 72% in both areas, and ostracods the second most abundant prey organisms (〉13%). The results of stomach content analyses reveals that most of gonostomatids, including two important species, Cyclothone braueri and C. microdon, feed continuously regardless of light cycle and a little at a time. The gonostomatids appear to be planktivores that consume small-sized prey; relative size of most preys was about one-tenth of fish length. These feeding patterns could be an adaptive characteristic of fish living in great deep water where the food items are scarcely present. In general there are no considerable inter-and intraspecific differences, not to mention regional differences, in the feeding of the gonostomatids at both stations except the large specimen of Gonostoma elongatum fed fish. Thus several coexisting species of the gonostomatid fish utilize the same resources, showing competitive relationships.

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N-Acetyl-D-Glucosamine Kinase Interacts with Dynein-Lis1-NudE1 Complex and Regulates Cell Division

  • Sharif, Syeda Ridita;Islam, Md. Ariful;Moon, Il Soo
    • Molecules and Cells
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    • v.39 no.9
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    • pp.669-679
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    • 2016
  • N-acetyl-D-glucosamine kinase (GlcNAc kinase or NAGK) primarily catalyzes phosphoryl transfer to GlcNAc during amino sugar metabolism. Recently, it was shown NAGK interacts with dynein light chain roadblock type 1 (DYNLRB1) and upregulates axo-dendritic growth, which is an enzyme activity-independent, non-canonical structural role. The authors examined the distributions of NAGK and NAGK-dynein complexes during the cell cycle in HEK293T cells. NAGK was expressed throughout different stages of cell division and immunocytochemistry (ICC) showed NAGK was localized at nuclear envelope, spindle microtubules (MTs), and kinetochores (KTs). A proximity ligation assay (PLA) for NAGK and DYNLRB1 revealed NAGK-dynein complex on nuclear envelopes in prophase cells and on chromosomes in metaphase cells. NAGK-DYNLRB1 PLA followed by Lis1/NudE1 immunostaining showed NAGK-dynein complexes were colocalized with Lis1 and NudE1 signals, and PLA for NAGK-Lis1 showed similar signal patterns, suggesting a functional link between NAGK and dynein-Lis1 complex. Subsequently, NAGK-dynein complexes were found in KTs and on nuclear membranes where KTs were marked with CENP-B ICC and nuclear membrane with lamin ICC. Furthermore, knockdown of NAGK by small hairpin (sh) RNA was found to delay cell division. These results indicate that the NAGK-dynein interaction with the involvements of Lis1 and NudE1 plays an important role in prophase nuclear envelope breakdown (NEB) and metaphase MT-KT attachment during eukaryotic cell division.

Studies on Distribution of Dung Beetles and Livestock Dung in Grazing Pasture (방목초지에서 가축 배설분과 분충류의 분포에 관한 연구)

  • Kim Meng Jung;Yook Wan Bang;Lim Yung Chul;Yoon Sei Hyung;Kim Jong Geun;Seo Sung;Lee Sang Moo
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.25 no.1
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    • pp.51-56
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    • 2005
  • The dung beetle species living in grazing pasture in Korea and their life cycle such as characteristics of habitation and hibernation were investigated for five year. Eleven species belonging to five genera of dung beetles were found in the grazing pasture. They started to appear around the middle of April when grazing begins on pasture. Dung booties kept on laying eggs until the beginning of August and maintained their activity until the end of October. They passed the winter as a form of an imago twenty five to thirty centimeters under the ground. Loamy soil and sandy soil containing plenty of humus were prefered as a hibemaculum by them. Five genera of dung beetles. Aprodius spp, Onthophagus spp., Liatongus spp., Copris spp., Scarabaeus spp. were found and observed in s study. Three species of them like Scarabaeus affinis had more an twenty eight millimeter long body, and the body length of five species like Copris tripartitus were between ten and twenty millimeters. Three species of them like Apodius sublimbatus were had the body length of less than ten millimeters. The results of indoor experiments to study propagation power of dung beetle showed that the optimum temperature for propagation of Copris ochus and Copris tripartitus were between twenty and thirty degrees and the lowest temperature for living of dung beetle was eighteen degrees while e highest temperature being thirty five degrees. A light did not effect the propagation power of dung beetles.

The Effect of Compressive Residual Stress according to Corrosion Fatigue Life of Automobile Suspension Material (자동차 현가장치재의 부식피로수명에 따른 압축잔류응력의 영향)

  • Ki, Woo-Tae;Park, Sung-Mo;Moon, Kwang-Seok;Park, Kyeong-Dong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.5
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    • pp.1-7
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    • 2008
  • A study of new materials that are light-weight, high in strength has become vital to the machinery of auto industries. But then, there are a lot of problems with developing such materials that require expensive tools, and a great deal of time and effort. Therefore, the improvement of fatigue strength and fatigue life are mainly focused on by adopting residual stress. And Influence of corrosive condition for corrosion fatigue crack was investigated, after immersing in 3.5%NaCl, 10+3.5%HF, 6. The immersion period was performed for 365days. The compressive residual stress was imposed on the surface according to each shot velocity based on shot peening, which is the method of improving fatigue life and strength. Fatigue life shows more improvement in the shot peened material than in the un peened material in corrosion conditions. The threshold stress intensity factor range was decreased in corrosion environments over ambient. Compressive residual stress of surface on the Shot-peen processed operate resistance force of fatigue crack propagation. The fatigue crack growth rate of the Shot-peened material was lower than that of the un peened material. Also m, fatigue crack growth exponent and number of cycle of the shot peened material was higher than that of the un peened material. That is concluded from effect of da/dN.

A Study on the Industry Food Service Management Practice in Chonbuk Province (산업체 단체급식소의 급식관리실태에 대한 조사연구)

  • 유정희
    • Korean journal of food and cookery science
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    • v.9 no.2
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    • pp.109-115
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    • 1993
  • This study was attempted to investigate the current status of industry food service management in Chonbuk province. The survey for the analysis was conducted through the questionaires to dietitian. The following results are to be noted. 1. Only one dietitian was employed regardless of feeding numbers and feeding times, and the average number of cooks comes to 5∼6 persons. Among 51 food service places for the study, 84.3% provided more than two meals a day. Feeding number were 200∼1000 people per one meal (64.7%) and feeding cost amounts to 700∼1000 won per meal per one person. 2. The food preferences and budget were primary considerations in menu planning. The type of menus was a non-selective menu with a seven-day cycle (83.7%). Most of dietitian (94.1%) had control of food purchasing, receiving and checking procedure and prefered placing orders by phone (94.5%) through the purveyors (86.4%). 3. In many food service places (70.5%), the mass food preparation was controlled of cooking method and standardized recipes were not undertaken by management Also, the food quality control such as flavor, texture, appearance and temperature was not fully established in food service system. 4. They used the method of manual dish washing operations (88%) and about 71.4% of them are dependent on boiling method of ultrabiolet light for disinfection of kitchen utensils. 5. The performance rates of dietitian management responsibility showed as nutritional management 100%, working management 72.4%, sanitary management 85.6%, personnel management 64.5% and nutrition education 40.7%, but they did not perform the objective and systematic their own responsibility as specialized dietitian because only few dietitian used basic check list and management tools. In addition, dietitian (21.6%) worked beyond their field. In the result, only 54.9% dietitian have satisfied their own occupation and most of them emphasized on practical working in educational curriculums.

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The structure of the ductuli efferentes in the Korean native pheasant(Phasianus colchicus korpowi) (한국산 꿩의 고환수출소관의 구조)

  • Paik, Young-ki;Yang, Hong-hyun;Kim, In-shik;Park, Young-seok
    • Korean Journal of Veterinary Research
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    • v.37 no.1
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    • pp.25-39
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    • 1997
  • The morphology of the ductuli efferentes of the Korean native pheasants were observed in order to obtain a basic data for further studying reproductive physiology and other male genital organs. The mature (14-16 months after hatching) male pheasants were used in this study. The specimens from pheasants were collected on a monthly basis. The general morphological changes of the ductuli efferentes were observed with hematoxylineosin stain, and semithin section by light microscope. The ultrastructural changes of the ductuli efferentes were investigated with ultrathin section by transmission electron microscope. The results obtained are summarized as follows : 1. During the breeding season, the average height of ductuli efferentes epithelium was 23.45±2.34μm and was largely decreased by 17.85±2.01μm during the non-breeding season. The thickeness of interstitial tissue was comparatively increased during the non-breeding season. 2. During the breeding season, the epithelial cells of ductuli efferentes were well developed. During the non-breeding season, epithelial layer and lumen of ductuli efferentes, were markedley reduced compared with those of breeding season. 3. Morphological changes of the ductuli efferentes underwent periodic changes paralleling to the spermatogenic cycle. 4. At least two different cell types were identified in the epithelium of ductuli efferentes, namely non-ciliated and ciliated cells. 5. The ciliated cells possess many vesicles, slightly smaller than those of the non-ciliated cells. 6. The ciliated cells contained numerous mitochondria, smooth and rough endoplasmic reticulum, Golgi complex, lysosome, and oval nuclei. The non-ciliated cells had a irregular nuclei and a cytoplasm containing few organelles. 7. During the breeding season, a number of vesicles, rough and smooth endoplasmic reticulum, Golgi complex, and mitochondria were distinctively showed in the epithelial cells but in the non-breeding season only a few observed.

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Higher Biomass Productivity of Microalgae in an Attached Growth System, Using Wastewater

  • Lee, Seung-Hoon;Oh, Hee-Mock;Jo, Beom-Ho;Lee, Sang-A;Shin, Sang-Yoon;Kim, Hee-Sik;Lee, Sang-Hyup;Ahn, Chi-Yong
    • Journal of Microbiology and Biotechnology
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    • v.24 no.11
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    • pp.1566-1573
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    • 2014
  • Although most algae cultivation systems are operated in suspended culture, an attached growth system can offer several advantages over suspended systems. Algal cultivation becomes light-limited as the microalgal concentration increases in the suspended system; on the other hand, sunlight penetrates deeper and stronger in attached systems owing to the more transparent water. Such higher availability of sunlight makes it possible to operate a raceway pond deeper than usual, resulting in a higher areal productivity. The attached system achieved 2.8-times higher biomass productivity and total lipid productivity of 9.1gm2day1 and 1.9gm2day1, respectively, than the suspended system. Biomass productivity can be further increased by optimization of the culture conditions. Moreover, algal biomass harvesting and dewatering were made simpler and cheaper in attached systems, because mesh-type substrates with attached microalgae were easily removed from the culture and the remaining treated wastewater could be discharged directly. When the algal biomass was dewatered using natural sunlight, the palmitic acid (C16:0) content increased by 16% compared with the freeze-drying method. There was no great difference in other fatty acid composition. Therefore, the attached system for algal cultivation is a promising cultivation system for mass biodiesel production.

Optimal Design of a Novel Knee Orthosis using a Genetic Algorism (유전자 알고리즘을 이용한 새로운 무릎 보장구의 최적 설계)

  • Pyo, Sang-Hun;Yoon, Jung-Won
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.10
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    • pp.1021-1028
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    • 2011
  • The objective of this paper is to optimize the design parameters of a novel mechanism for a robotic knee orthosis. The feature of the proposed knee othosis is to drive a knee joint with independent actuation during swing and stance phases, which can allow an actuator with fast rotation to control swing motions and an actuator with high torque to control stance motions, respectively. The quadriceps device operates in five-bar links with 2-DOF motions during swing phase and is changed to six-bar links during stance phase by the contact motion to the patella device. The hamstring device operates in a slider-crank mechanism for entire gait cycle. The suggested kinematic model will allow a robotic knee orthosis to use compact and light actuators with full support during walking. However, the proposed orthosis must use additional linkages than a simple four-bar mechanism. To maximize the benefit of reducing the actuators power by using the developed kinematic design, it is necessary to minimize total weight of the device, while keeping necessary actuator performances of torques and angular velocities for support. In this paper, we use a SGA (Simple Genetic Algorithm) to minimize sum of total link lengths and motor power by reducing the weight of the novel knee orthosis. To find feasible parameters, kinematic constraints of the hamstring and quadriceps mechanisms have been applied to the algorithm. The proposed optimization scheme could reduce sum of total link lengths to half of the initial value. The proposed optimization scheme can be applied to reduce total weight of general multi-linkages while keeping necessary actuator specifications.

Photoelectrochemical Water Oxidation Using ZnO Nanorods Coupled with Cobalt-Based Catalysts

  • Jeon, Tae-Hwa;Choi, Sung-Kyu;Jeong, Hye-Won;Kim, Seung-Do;Park, Hyun-Woong
    • Journal of Electrochemical Science and Technology
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    • v.2 no.4
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    • pp.187-192
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    • 2011
  • Photoelectrochemical performances of ZnO electrodes are enhanced by coupling with cobalt-based catalyst (CoPi) in phosphate electrolyte (pH 7). For this study, hexagonal pillar-shaped ZnO nanorods are grown on ZnO electrodes through a chemical bath deposition, onto which CoPi is deposited with different photodeposition times (10-30 min). A scanning electron microscopic study indicates that CoPi deposition does not induce any change of ZnO morphology and an energy-dispersive X-ray spectroscopic analysis shows that inorganic phosphate ions (Pi) exist on ZnO surface. Bare ZnO electrodes generate the current of ca. 0.36mA/cm2 at a bias potential of 0.5 V vs. SCE, whereas ZnO/CoPi (deposited for 10 min) has ca. 50%-enhanced current (0.54mW/cm2) under irradiation of AM 1.5G-light (400mW/cm2). The excess loading of CoPi on ZnO results in decrease of photocurrents as compared to bare ZnO likely due to limited electrolyte access to ZnO and/or CoPi-mediated recombination of photogenerated charge carriers. The primary role of CoPi is speculated to trap the photogenerated holes and thereby oxidize water into molecular oxygen via an intervalency cycle among Co(II), Co(III), and Co(IV).

Development and Characteristic Study of a Portable Gas Chromatography (소형 GC 모듈의 개발 및 특성)

  • Lee, Myeong-Gi;Oh, Jun-Sik;Jung, Kwang-Woo
    • Journal of the Korean Chemical Society
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    • v.55 no.2
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    • pp.157-162
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    • 2011
  • In the present study, we developed a portable GC module for real-time, quantitative determinations of gas mixtures in air sample. Capillary or packed column was coiled together with a heater wire and thermocouple in a small case. Together with the small and light weight sensors and valves as well as the rechargeable carrier gas canister, which permits collection and separation of samples, this system can determine the components of complex mixtures of air contaminants at low concentrations with a duty cycle of 10 min. When measured the various samples with a FID and TCD, the system showed, for a capillary column, a good resolution (R=8.3), high sensitivity, reproducibility, and linear dynamic range greater than three orders of magnitude. These results indicate that the portable GC module is expected to be used for a wide range of applications, particularly for in situ environmental monitoring, chemical processes, and regulation of contaminant emission.