• Journal of the Mineralogical Society of Korea
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• v.25 no.4
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• pp.271-282
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• 2012

We explore the effect of removal of organic ligand on the atomic configurations around oxygen in hydroxyl groups in amorphous silica gel (synthesized through hydrolysis of $SiCl_4$ in diethyl-ether) using high resolution $^{17}O$ solid state NMR spectroscopy. $^1H$ and $^{29}Si$ MAS NMR spectra for amorphous silica gel showed diverse hydrogen environments including water, hydroxyl groups (e.g., hydrogen bonded silanol, isolated silanol), and organic ligands (e.g., alkyl chain) that may interact with surface hydroxyls in the amorphous silica gel, for instance, forming silica-organic ligand complex (e.g., Si-$O{\cdots}R$). These physically and chemically adsorbed organic ligands were partly removed by ultrasonic cleaning under ethanol and distilled water for 1 hour. Whereas $^{17}O$ MAS NMR spectra with short pulse length ($0.175{\mu}s$) at 9.4 T and 14.1 T for as-synthesized amorphous silica gel showed the unresolved peak for Si-O-Si and Si-OH structures, the $^{17}O$ MAS NMR spectra with long pulse length ($2{\mu}s$) showed the additional peak at ~0 ppm. The peak at ~0 ppm may be due to Si-OH structure with very fast relaxation rate as coupled to liquid water molecules or organic ligands on the surface of amorphous silica gel. The observation of the peak at ~0 ppm in $^{17}O$ MAS NMR spectra for amorphous silica gel became more significant as the organic ligands were removed. These results indicate that the organic ligands on the surface of amorphous silica gel interact with oxygen atoms in Si-OH and provide the information about atomic structure of silanol and siloxane in amorphous silica gel. The current results could enhance the understanding of dehydration mechanism of diverse silicates, which is known as atomic scale origins of intermediate depth (approximately, 70~300 km) earthquakes in subduction zone.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.3
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• pp.98-104
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• 2010

The objective of this study was to understand the origin and characteristics of stone tower's style through the study of the 'Village Shrine at Seoji-ri, Andong'. The three kinds of stone towers were located forming a line of 9m on the hill of a red pine forest along the stream in the village. Toward the direction looking at the village, the three-story stone located on left, the two-story stone located in the middle, and the common style stone tower located on right. The bottom part of the three-story stone was 2.5m in length, 1.8m in width, 1.3m in height. The bottom part of the two-story stone was 1.3m in length, 1.5m in width, 0.9m in height. The common style stone heap tower was 3.0m in diameter, 1.8m in height with a cone shape. The small hat-shaped stone was presumed to be the top part of a three-story stone. According to the three factors(heaven, earth, human) of the idea of the universe in Korea, most ancient remains have components of odd numbers. Then it had been substituted with smaller three-story stone(at present, two-story stone). And then altered to a common stone tower later, such as the 'Village Shrine at Seoji-ri, Andong' that shows the combination of the Bronze Age's megalithic and a folk religion. The 'Village Shrine at Seoji-ri, Andong' is a valuable relic that shows the stone towers, and is derived from the Bronze Age. The 'Village Shrine at Seoji-ri, Andong' shows that the 'Village Shrine at Seoji-ri, Andong' was embodied the three-factor(heaven, earth, human) idea of the universe in three-story stone of megalithic culture' remains.

• Analytical Science and Technology
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• v.13 no.4
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• pp.494-503
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• 2000

A 21-residue peptide corresponding to amino acids 84-104 of $p16^{INK4A}$, the tumor suppressor, has been synthesized and its structure was studied by Circular Dichroism, $^1H$ NMR spectroscopy and molecular modeling. A p16-derived peptide (84-104 amino acids) forming stable complex with CDK4 and CDK6 inhibits the ability of CDK4/6 to phosphorylate pRb in vitro, and blocks cell-cycle progression through G1/S phase as shown in the function of the full-length p16. Its NMR spectral data including NOEs, $^3J_{NH-H{\alpha}}$ coupling constants, $C_{\alpha}H$ chemical shift, the average amplitude of amide chemical shift oscillation and temperature coefficients indicate that the secondary structure of a p16-derived peptide is similar to that of the same region of full-length p16, which consists of helix-turn-helix structure. The 3-D distance geometry structure based on NOE-hased distance and torsion angle restraints is characterized by ${\gamma}$-turn conformation between residues $Gly^{89}-Leu^{91}$(${\varphi}_{i+1}=-79.8^{\circ}$, ${\varphi}_{i+1}=60.2^{\circ}$) as evidenced in a single crystal structure for the corresponding region of p18 or p19, but is undefined at both the N and C termini. This compact and rigid ${\gamma}$-turn region is considered to stabilize the structure of p16-derived peptide and serve as a site recognizing cyelin dependent kinase, and this well-defined ${\gamma}$-turn structure could be utilized for the design of anti-cancer drug candidates.

• Journal of the Mineralogical Society of Korea
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• v.6 no.2
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• pp.57-79
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• 1993

Chuncheon nephrite, which was formed by the polymetasomatic alteration of dolomitic marble, can be classified into pale green, green, dark green, and grey types on the basis of their occurrence, mineralogical and textural characteristics. The nephrites consist obiefly of fibrous or hairlike(length/width ratio>10) cryptocrystalline(crystal width < $2{\mu}m$) tremolite, and include less amounts of micro-crystalline diopside, calcite, clinochlore, and sphene as impurities. The oriented and rather curved crystal aggregate, of nephritic tremolite are densely interwoven, resulting in a massive-fibrous texture which may explain the characteristic toughness of nephritic jade. The characteristic greenish color of the nephrite may be preferably related to Fe rather than Cr and Ni. However, the variation of color and tint in the Chuncheon nephrite also depends on the mineralogical and textural differences such as crystallinity, texture, and impurities. The chemical composition of the nephritic tremolite is not stoichiometric and rather dispersed especially in the abundances of Al, Mg, and Ca. Al content and Mg/Ca ratio for the nephritic tremolite are slightly increased with deepening in greenish color of the nephrite. Fe content in the nephritic tremolite is generally very low, but comparatively richer in the dark green nephrite. In nephritic tremolite, wide-chain pyriboles are irregularly intervened between normal double chains, forming a chain-width disorder. Most nephritic tremolites in the Chuncheon nephrite show various type of chain-width defects such as triple chain(jimthompsonite), quintuple chain (chesterite), or sometimes quadruple chain in HRTEM observations. The degree of chain-width disorder in the nephritic tremolite tends to increase with deepening in greenish color. Triple chain is the most common type, and quadruple chain is rarely observed only in the grey nephrite. The presence of pyribole structure in the nephritic tremolite is closely related to the increase of Al content and Mg/Ca ratio, a rather dispersive chemical composition, a decrease of relative intensity in (001) XRD reflection, and an increase in b axis dimension of unit cell. In addition, the degree and variation of chain-width disorder with nephrite types may support that an increase of metastability was formed by a rapid diffusion of Mg-rich fluid during the nephrite formation.

• Parasites, Hosts and Diseases
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• v.27 no.4
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• pp.261-270
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• 1989

The present study is intended to observe the chronologic changes of experimental sparganosis by histopathological observation and detection of circulating anti-sparganum IgG antibody using ELISA. Each of 25 mice was infected with aye spargana, and they were examined after 1, 2, 4, 10 weeks or 6 months from infection. The followings are summarized results. - 1. The plerocercoids were detected in the subcutaneous tissue of the trunk, neck or axilla, but a few often extended into the skeletal muscle. The recovery rates were 72% at the first week, 80% at the second week, 95% at the fourth week, 92% at the tenth week and 100% at .the sixth month. The larvae grew slowly in both length and weight until 6 months. 2. Histopathologically, most of the larvae were observed alive in the soft tissue or skeletal muscle. Numerous eosinophils, neutrophils, Iymphocytes and plasma cells were infiltrated focally around the worms by the second week, but they surrounded the worms to form a layer of inflammatory reaction after 4 weeks of infection. Also histiocytes and fibroblasts began to appear around the inflammatory cells at 4 weeks. After 10 weeks, the worms encircled by a thin fibrous layer were found. After 6 months, the worms were surrounded by either fibrous tissue or active inflammatory cells. The inflammation looked more severe in the tracks left by the worms, rather than around the worms. 3, The level of anti-sparganum IgG antibody in the serum showed an increase by the fourth week, and a rapid and continuous increase was observed thereafter by the tenth week after infection. The high level of the IgG antibody was maintained up to 6 months forming a plateau curve. The present results suggest that the tissue reaction and antibody production in subcutaneous sparganosis become distinctive by the fourth week after infection.

• Applied Microscopy
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• v.31 no.4
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• pp.333-345
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• 2001

The mature sperms of three species of cephalopods (Octopus minar, Octopus ocellatus, Todarodes pacificus) were observed by electron microscopy. The results obtained are as follows: The sperm lengths of Octopus minor and Octopus ocellatus of octopods are long and they are about $390{\mu}m$ and $125\sim130{\mu}m$, respectively, but the sperm length of Todarodes pacificus is short and about $35{\mu}m$. The sperm of Octopus minor has a helical acrosome and a head bent a little like a banana while Octopus ocellatus of octopod has a twisted acrosome and a long rod-shaped head. A number of horizontal stripes are observed as a periodic structure in their subacrosome cavities and dense plugs are formed in the cavities of their heads. On the other hand, the acrosome of Todarodes pacificus is circular cap-shaped, and its head is long and oval. It is notable that two small cavities were observed in its basal acrosome. Juxtanuclear acrosomal materials of high electron density filled the subacrosomal cavity. In the middle piece of mature sperms of Octopus minor and Octopus ocellatus, the mitochondria form the mitochondrial sleeve, but the numbers of mitochondria differ between the species so that they are $11\sim12$ and $8\sim9$, respectively. Meanwhile, in the middle piece of mature sperms of Todarodes pacificus, the mitochondria are separated from the axoneme, forming a mitochondrial spur in which $10\sim13$ mitochondria and some electron dense materials concentrate. The axoneme of Octopus minor, Octopus ocellatus and Todarodes pacificus are of 9+2 type in common, surrounded by 9 coarse fibres. A number of glycogen were observed only in the axoneme of Todarodes pacificus. The coarse fibres were found as far as the main piece of sperm tail in Octopks minor and Todarodes pacificus, while to the end piece of sperm tail in Octopus ocellatus.

• Korean Journal of Cognitive Science
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• v.29 no.2
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• pp.121-135
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• 2018

Dancers' motions are perceived by observers through visual processes with visual information forming the basis for the observers' appreciation and evaluation of the dancers' motions. There have been many discussions as to whether or not observers' personal athletic capabilities form an essential basis for accurate assessment of the motions of others but, so far, no valid conclusions have been reached. The purpose of this study is to investigate how the ability to predict motions of others varies depending on the athletic expertise of the observers. Participants of this research were ballet dancers of varying athletic expertise. Twenty seven participants were divided into three groups with nine in each: beginners, intermediate experts and experts. The participants watched the same dance video and then evaluated whether the motion would be successful or not. The movement related visual information required to evaluate the success of the motion was systematically adjusted by controlling the length of the video. Using the temporal occlusion method, this study measured the response accuracy of the participants by category of expertise. Under the circumstance with insufficient visual information to utilize, the experts showed higher rates of correct response than the intermediate experts and the beginners. The beginners showed higher rates of wrong response than the experts and the intermediate experts. These results showed that the ability to predict success or failure of a dance motion varied depending on motion expertise of the observers, although they had similar level of expertise in perception. Participants considered to have high athletic expertise showed high prediction ability on the result of the motion. In addition, high expertise in perception reduced the likelihood that participants would make hasty responses under the circumstance with insufficient information and helped to reduce wrong response rate. In conclusion, this study showed that motor expertise and perceptual expertise contribute to prediction accuracy of observed motions.

• Korean Journal of Ecology and Environment
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• v.47 no.4
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• pp.350-357
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• 2014

Harmful Algal Bloom Alert System (HABAS) for drinking water supply is require to fast and accurate count as system monitoring of cyanobacterium occurrence and inducing a response action. We measured correlation between colony size and cell number including genus Anabaena, Aphanizomenon, Microcystis, Oscillatoria which are targeted at HABAS, deducted from standard formula, and suggested calculation method from colony size to the number of cell. We collected cyanobacteria samples at Han River (Paldang reservoir), Nakdong River (Dalseong weir, Changnyeonghaman weir) and Geum River (Gobok reservoir) from August to October, 2013. Also, we studied correlation between colony size and cell number, and calculated regression equation. As a result of correlation of harmful cyanobacteria by genus, Anabaena spp. and Aphanizomenon spp. having trichome showed high correlation coefficients more than 0.93 and Microcystis spp. having colony showed correlation coefficient of 0.76. As a result of correlation of harmful cyanobacteria by species, Anabaena crassa, Aphanizomenon flos-aquae, A. issatschenkoi, Oscillatoria curviceps, O. mougeotii having trichome showed high correlation coefficients from 0.89 to 0.96, and Microcystis aeruginosa, M. wessenbergii, M. viridis having colony showed correlation coefficients from 0.76 to 0.88. Compared with other genus Microcystis relatively showed low correlation because even species and colony size are the same, cell density and cell size are different from Microcystis strains. In this study, using calculated regression might be fast and simple method of cell counting. From now on, we need to secure additional samples, and make a decision to study about other species.

• Journal of Aquaculture
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• v.4 no.1
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• pp.31-66
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• 1991

This paper deals with the reproductive ecology e.g., number of the pre-spawning moults, morphological characteristics of the pre-spawning moult the common moult, daily ration druing a molting cycle mating behavior, structures of spermatozoa and spermatophore, structure of vas deferens, mechanisms of the oviposition and brooding into the egg-chambers, a suitable time for the artificial mating and fertilization, time sequence of the oviposition and brooding into egg-chambers from the copulation, responses to temperature and chlorinity on the egg development and hatching, effect of temperatures on duration of egg development, physical mechanism of the egg hatching, to make an attempt for the artificial spawning and brooding to establish a suitable system of the artificial seedling-production for the aquaculture. 1. Females molted commonly $8{\~}10$ times at an interval of $17{\~}18$ days at $28^{\circ}C,\;3.26\~4.35\%_{\circ}$ while the prespawning moltings were $4{\~}5$ times at an interval of $13{\~}14$ days. The suitable state for artificial copulation was within 14 hours elapsed from the prespawning moltings (most suitable state was within 8 hours). Males discharged a gelatinous spermatophore and placed it on the females sternum during copulation. Oviposition was seen $6{\~}17$ hours after copulation. External fertilization was considered to take place at oviposition. Fertilized eggs held in egg-chambers forming between pleopods were about $5000{\~}6000$ in females those sizes about 6.5 cm in body length. 2. Eggs immediately after oviposition were elliptic shape, measuring $0.58{\times}0.48$ mm up to hatching. Their sizes increased with egg development and finally reached $0.85{\times}0.54$ mm up to hatching. The relationship between the long axis of the egg(Y in U) and days elapsed(X) was expressed as Y= 5.60194 + 0.007358X. The eggs performed superficial cleavage and their cleavage furrows became visible at the 4-daughter-nucleus stage. The eggs showed normal development up to hatching at water temperature range of $22{\~}30^{\circ}C$ (optimum temperature : $26{\~}28^{\circ}C$) and at chlorinity range of $0.00\~6.64\%_{\circ}$ (optimun chlorinity : $2.21{\%}_{\circ}$). The relationship between incubation period (Y in days) and water temperature(X in $^{\circ}C$) could be expressed as Y= 50.803-1.3555X. The eggs hatched $12{\~}13$ days after oviposition at $28.0{\~}28.6^{\circ}C$ 3. The pre-spawning moltings were appreciably different in the morphologic structure from those of common moltings. Breeding setae and dresses were formed on the thoracic regions, abdominal epimerae and the bases of the first to fourth pleopods in order to prepare and support oviposition, transfering and supporting eggs in egg-chambers up to hatching. These supplementary breeding organs were observed only at reproductive seasons.

• Applied Microscopy
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• v.38 no.2
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• pp.117-124
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• 2008

Salvinia is an aquatic plant forming dimorphic leaves that have been modified into floating and submerged leaves. A air of floating leaves plays an important role for the floating and photosynthesis while the submerged leaves, which are lim and long, have the form and function of root. Many aquatic plants develop trichomes in the epidermis but in Salvinia, richomes grow densely in the epidermis of the dimorphic leaves. The present study examined the differentiation pattern of trichomes developing in the floating leaves of S. natans and S. molesta by scanning and transmission electron microscopy. Trichomes developing in the floating leaves of Salvinia showed very different patterns. In S. natans, they were arranged in a V-shape form, having 20${\sim}$25 rows at $18{\sim}25^{\circ}$ on both sides of the lamina divided by the midrib in the floating leaf. In each row, 8${\sim}$10 oval-shaped cells, $200{\sim}290{\mu}m$ in length, were arranged in a spiral fashion. Four trichomes of this form made a trichome unit, but their apical parts were separated from one another and developed into the so-called 'knuckle-crane' type. On the other hand, in S. molesta, trichomes differentiated in a unique pattern quite different from those of S. natans. At the early stage of differentiation, trichomes protruded from the epidermis and then 4${\sim}$6 cylindrical cells grew $400{\sim}600{\mu}m$ long and the four trichomes formed as an unit. The four grouped trichomes were interconnected through their apex and developed in the 'egg-beater' type. Then $300{\sim}600{\mu}m$ long multi-cellular stalk cells grew and protruded out of the epidermal surface from the basal part of the trichomes. Such a structural characteristic of trichomes is considered to play a very important role along with the aerenchyma tissue in the leaf mesophyll tissue for the floating of Salvinia on the water surface.