• Journal of fish pathology
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• v.18 no.1
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• pp.29-37
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• 2005

This study investigated external symptoms, behavior characteristics and the distribution pattern of the scuticociliates in the skin, gill and blood vessel of the tiger puffer, Takifugu rubripes, infected with scuticociliates among tiger puffer cultured. The fish infected with scuticociliates did not show any external symptoms, such as change in body color or swimming behavior, in the early infection stage. However, they showed congestion, erosion, and ulcer on the skin and fin at advanced stages. They showed a turning movement, mainly stayed on the bottom, and swam with their mouths open at the surface of water. Some fish showed a sudden swimming movement of zigzag type. The scuticociliates were ovoid in shape and $20\times40{\mu}m$ in size. The scuticociliates had a contractile vesicle and a caudal cilium that ranged 10-12 ${\mu}m$, and reproduced by binary fission. Therefore the scuticociliates were identified as ciliated, belonging to class Hymenostomatia, order Scuticociliatida in morphogenetic character. The gills infiltrated with scuticociliates showed clubbed gill filament due to hypertrophy of gill lamella. Within the blood vessels, scuticociliates were observed one to ten individuals, depending on diameter of the blood vessels. Some of the scuticociliates were observed to have ingested erythrocytes.

• Applied Microscopy
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• v.42 no.1
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• pp.17-26
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• 2012

Histologic and microstructural changes during the postembryonic development of the wolf spider Arctosa kwangreungensis were studied using light and scanning electron microscopy to examine the relationship between a morphological differentiation and behavioral properties. The postembryo with abdominal yolk sac was stayed inactive in the egg case because its muscular and visual systems were not fully developed to a functional level. The first instar spiderlings, developed from the postembryo by a first molting process, started to exhibit its pigmentation on their body cuticles. In particular, undifferentiated cell clusters of central nervous system (CNS) were densely distributed within the cephalothorax, and highly differentiated abdominal ganglion was observed. They had a characteristic visual system looks more like its adult counterpart, and had segmented appendages looks more like the tiny spiders containing well oriented muscular system. After 3rd instar, spiderlings grew more rapidly with accordance to their consistent growth and periodical molting processes. Thus, the relative area of CNS with respect to cephalothorax was gradually decreased, instead a pair of venom glands, musculature, and connectives occupied the residual area. It has been revealed that the early development of spider can be controled by the feeding condition of larval period, since histologic and microstructural differentiations in both appendages and optic system were completed at the second instar. In particular, behavioral properties of the wandering spiders that depend on vision and their running ability were deeply related to physiological differentiation of the microstructural development.

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.2
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• pp.122-131
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• 2010

This paper introduces the concept of a virtual ecosystem and reports the following three mathematical approaches that could be widely used to construct such an ecosystem, along with examples: (1) a molecular dynamics simulation approach for animal flocking behavior, (2) a stochastic lattice model approach for termite colony behavior, and (3) a rule-based cellular automata approach for biofilm growth. The ecosystem considered in this study consists of artificial organisms and their environment. Each organism in the ecosystem is an agent that interacts autonomously with the dynamic environment, including the other organisms within it. The three types of model were successful to account for each corresponding ecosystem. In order to accurately mimic a natural ecosystem, a virtual ecosystem needs to take many ecological variables into account. However, doing so is likely to introduce excess complexity and nonlinearity in the analysis of the virtual ecosystem's dynamics. Nonetheless, the development of a virtual ecosystem is important, because it can provide possible explanations for various phenomena such as environmental disturbances and disasters, and can also give insights into ecological functions from an individual to a community level from a synthetic viewpoint. As an example of how lower and higher levels in an ecosystem can be connected, this paper also briefly discusses the application of the second model to the simulation of a termite ecosystem and the influence of climate change on the termite ecosystem.

• Journal of Korean Society of Forest Science
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• v.78 no.1
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• pp.42-54
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• 1989

These studies were carried out to examine the anatomical, karyological characteristics, the variation of isozymes in needle and the frost damage of tissue for the purpose of investigating the relationships among the three natural Torreya nucifera populations of Cheju-do, Namhae, and Mt. Naejang in Korea. The results obtained can be summed up as follows : 1. The numbers of endodermal cells and inner layer cells of mucilage canal of needle conductive tissue were different in each population. The number of those of Cheju-do population was the largest. 2. In somatic chromosome, Namhae population showed one more secondary constriction. The values of $b^{arm}/a^{arm}$ were the same in all the three populations, but Cheju-do population particularly showed a different minimum value. And the karyotype formulas of each population showed difference. 3. During the meiosis, each population showed no significant difference in the irregular phenomena of chromosome. 4. In isoperoxidase and esterase variations of needle, each population showed its particular number and variation of bands. Cheju-do population showed the largest number and greatest variation of bands. 5. Under the same freeging conditions, the frost damage of Mt. Naejang population was comparatively slight, and Cheju-do population suffered from a greater frost damage than the others.

• Journal of Genetic Medicine
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• v.5 no.1
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• pp.65-68
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• 2008

Molecular cytogenetics allows the identification of unknown chromosome rearrangements, which is clinically useful in patients with mental retardation and/or development delay. We report on a 31-year-old woman with severe mental retardation, behavior development delay, and verbal performance delay. Conventional cytogenetic analysis showed a 46,XX,add(8)(p23.3) karyotype. To determine the origin of this unbalanced translocation, we performed array CGH and subtelomeric FISH. The results showed that the distal region of chromosome 8p was added to the terminal of chromosome 13q. This was confirmed the final result of 46,XX,der(8)t(8:13)(p23.3;q32.1)dn.

• Development and Reproduction
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• v.16 no.2
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• pp.101-106
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• 2012

Importance of behavior factors or environmental factors in visual organization and visual function of fish is treated with great care in visual ecology, and there is no study about initial ocular growth and development on the dark banded rockfish, Sebastes inermis. Thus, this study was performed. The total length, head length, head depth, eye diameter and lens diameter of the dark banded rockfish showed positive allometric relationship between parturition stage and 60 days post-parturition (dpp). The increase in total length relative to head length and head depth, head length growth relative to eye diameter and lens diameter, and head depth growth relative to eye and lens diameter were nearly isometric. The eyes were formed completely at parturtion stage. At this age, the eye has an optic nerve fiber layer, a ganglion cell layer, an inner plexiform layer, an inner nuclear layer, an outer plexiform layer, an outer nuclear layer, an outer limiting membrane, a rod and cone layer and an epithelial layer. Thickness of retina at 60 dpp was higher than that of at parturition stage. During this experiment, the proportion of the rod and cone layer, outer nuclear layer, and optic nerve fiber layer of retina were significantly increased, while the proportion of the outer plexiform layer, inner nuclear layer and ganglion cell layer of retina were significantly decreased (P<0.05). The essential demands that must be met by the retina in this species pertain to light sensitivity and spatial resolution.

• Journal of Life Science
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• v.26 no.12
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• pp.1487-1497
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• 2016

Bacterial cell to cell communication strategies called quorum sensing (QS) using small diffusible signaling molecules (auto-inducers) govern the expression of various genes dependent on their population density manner. As a consequence of synthesis and response to the signaling molecules, individual planktonic cells synchronized group behaviors to control a diverse array of phenotypes such as maturation of biofilm, production of extra-polymeric substances (EPS), virulence, bioluminescence and antibiotic production. Many studies indicated that biofilm formations are associated with QS signaling molecules such as acyl-homoserine lactones (AHLs) mainly used by several Gram negative bacteria. The biofilm maturation causes undesirable biomass accumulation in various surface environments anywhere water is present called biofouling, which results in serious eco-technological problems. Numerous molecules that interfere the bacterial QS called quorum quenching (QQ), have been discovered from various microorganisms, and their functions and mechanisms associated with QS have also been elucidated. To resolve biofouling problems related to various industries, the novel approach based on QS interference has been emerged attenuating multi-drug resisting bacteria appearance and environmental toxicities, which may provide potential advantages over the conventional anti-biofouling approaches. Therefore this paper presents recent information related to bacterial quorum sensing system, quorum quenching enzymes that can control the QS signaling, and lastly discuss the anti-biofouling approaches using the quorum quenching.

• Applied Microscopy
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• v.38 no.4
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• pp.321-328
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• 2008

The main purpose of this study is to investigate the effects of electrolyzed reduced water (ERW) on blood components and electrolytes, as well as elected tissues on mice. The mice were supplied either tap water (control group) and ERW (experimental group) for two months. There were no significant different between two groups anatomically and physiologically. In the blood electrolyte study, the experimental group had less Na and BUN compared to the control group. In the blood component study, the experimental group had less neutrophiles and the control group had more lymphocytes. In histological study, no tissue changes were noticed in various organs, including the stomach, small intestine, heart, and liver tissues. In conclusion, ERW has no noticable side affects on blood and organ tissues, and might be safe to a living body.

• Journal of The Korean Association For Science Education
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• v.36 no.4
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• pp.617-628
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• 2016

This study aims to explore pre-service biology teachers' value orientation in terms of scientific observation and representation in plant cell microscope observation experiment. This study focuses on the pre-service teachers' value orientation in relation to objectivity. To achieve this aim, we used a hypothetical situation that pre-service teachers should teach tacit knowledge related to observation and representation during the cell observation class. We presented a hypothetical situation to fifty pre-service biology teachers and collected their answer about that hypothetical situation. These answers were categorized inductively based on constant comparative analysis. The result shows that four types of pre-service teachers' value orientation, 'presence confirmation', 'mechanical objectivity', 'students' subjectivity', and 'trained judgement', are confirmed. This result also shows that various value orientation could be reflected on teaching an experiment and tacit knowledge related to the experiment. Also, many pre-service teachers value 'mechanical objectivity' in observation and image representation. Also, pre-service teachers' value orientation and perception of objectivity in scientific practice could have an influence in teaching science, this result could give provide suggestions on science teachers' education in terms of scientific practice.

• Journal of Life Science
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• v.26 no.2
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• pp.164-173
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• 2016

Isotocin (IT), a nonapeptide homolog of oxytocin in mammals, has been suggested to be involved in physiological processes including social behaviors, stress responses, and osmoregulation in teleost fish. To study its structure and function, the gene encoding the IT precursor was cloned from the genomic DNA and brain cDNA of the cinnamon clownfish, Amphiprion melanopus. The IT precursor gene consists of three exons separated by two introns, and encodes an open reading frame of 156 amino acid (aa) residues, comprising a putative signal peptide of 19 aa, a mature IT protein of 9 aa, a proteolytic processing site of 3 aa, and 125 aa of neurophysin. Tissue-specific analysis of the IT precursor transcript indicated its expression in the brain and gonads of A. melanopus. To examine its osmoregulatory effects, the salinity of the seawater (34 ppt) used for rearing A. melanopus was lowered to 15 ppt. Histological analysis of the gills indicated the apparent disappearance of an apical crypt on the surface of the gill lamella of A. melanopus, as pavement cells covered the surface upon acclimation to the lower salinity. The level of Na⁺/K^+-ATPase activity in the gills was increased during the initial stage of acclimation, followed by a decrease to its normal level, suggesting its involvement in osmoregulation and homeostasis. The only slight increase in the level of IT precursor transcript in the A. melanopus brain upon low-salinity acclimation suggested that IT played a minor role, if any, in the process of osmoregulation.