• Environmental Analysis Health and Toxicology
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• 제22권3호
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• pp.189-196
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• 2007

[ $TiO_2$ ] is widely used because it is non-toxic. Recently, however, nanometer size $TiO_2$ particles (P-25) have been produced and used to increase the photo catalysis efficiency. Nanometer-sized $TiO_2$ is efficient, but due to its small size ($20{\sim}30\;nm$), it can flow into ecosystems and into cells. Thus, it may affect human health. Additionally, $TiO_2$ can produce a second contaminant, OH-radical, which is a health risk for all living organisms during photo degradation reaction. Hence, when nanometer-sized $TiO_2$ flows into natural streams and attaches to living organisms, it will create health risks. We investigated the biological toxicity of this condition in zebrafish embryos. We observed abnormal morphology, hatching rate, and measured the catalase activity to determine anti-oxidation at 100 post fertilization hours. Zebrafish were somewhat affected by $TiO_2$ nanometer sized particles under UV-A (a condition similar to sunlight). Powdered $TiO_2$ is toxic to the zebrafish fly. Even without light, $TiO_2$ particles attached to embryos and flies, having an effect on both.

• 한국잡초학회지
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• 제18권2호
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• pp.85-94
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• 1998

Herbicides play a very important role in modern agriculture. However, the herbicide applied to the agricultural field may accumulate in the field, converting the advantages to environment pollution. Many small animals in the ecosystem such as alderfly, earthworm, butterfly, loach, frog, firefly, some birds and aquatic organisms have been known to disappear gradually. In addition, several behavior of herbicides including adsorption by soil, movement by water, photodecomposition, volatilization to air, absorption by plant, metabolism by soil microorganisms and so on, are proceeded while the herbicide remained in the environment. In this review, fate and behavior of herbicides in the environment and their effect on ecosystem after their application are focused on four aspects : the first is the absorption and metabolism of herbicides by plant; the second is the residues of herbicides in soil and water environments: the third is the accumulation and release of herbicides in aquatic organisms and the fourth is the translocation of herbicides in model agricultural ecosystem. Many factors may affect the behavior and fate of herbicides after their application, climatic conditions and soil properties seem to be the most important. Therefore, the fate and behavior of herbicide in Taiwan, located on subtropical region, may differ from those in Korea.

• 한국수산과학회지
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• 제32권1호
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• pp.10-17
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• 1999

1994년 1월부터 1994년 12월까지 광양만 대도주변 잘피밭에서 채집된 문절망둑의 식성을 조사하였다. 문절망둑의 주요 먹이생물은 갯지렁이류(Polychaeta), 게류(Brachyura), 새우류(Caridea), 옆새우류 (Gammaridea) 및 어류 (Pisces) 등 다양하였다. 그 외, 거미불가사리류 (Ophiuroidea), 복족류 (Castropoda), 이매패류 (Bivalvia), 카프렐라류 (Caprellidea), 집게류 (Anomura), 등각류 (Isopoda), 주걱벌레 붙이류 (Tanaidacea)등을 소량 먹었다. 문절망둑은 성장함에 따라 먹이생물 조성의 변화를 보였는데, 작은 체장에서는 갯지렁이류와 단각류를 주로 먹었다. 그러나 체장이 증가하면서 갯지렁이류와 단각류를 먹는 비율은 감소한 반면, 새우류, 게류 및 어류의 점유율은 증가하였다. 성어 단계에서는 매우 다양한 먹이생물을 먹는 것으로 나타났다. 계절에 따라 먹이생물의 조성이 변하였는데, 봄과 가을에는 갯지렁이류, 새우류 및 옆새우류의 점유율이 높았으나, 여름과 겨울에는 어느 특정 먹이생물이 우점하지 않고 비교적 고른 분포를 보였다.

• 한국어류학회지
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• 제20권1호
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• pp.36-44
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• 2008

2006년부터 2007년까지 옥정호에 도입된 외래어종 배스 Micropterus salmoides를 채집하여 식성을 조사하였다. 채집된 배스의 체장범위는 13~511 mm (n= 419)였다. 배스는 강한 육식성 어종으로 주로 어류를 섭식하였으며 그밖에 수서곤충과 새우류 등을 섭식하였다. 배스는 성장하면서 식성이 변하였는데, 10~20mm는 주로 지각류를 섭식하였고, 30~50 mm은 수서곤충과 소형어류를, 50 mm 이상의 개체는 피라미, 치리, 밀어와 같은 어류를 주로 섭식하였다. 1981년부터 옥정호의 어류상을 분석한 결과, 강한 육식성 어종인 배스의 도입은 옥정호 토착종의 다양도와 출현비율의 감소를 초래하는 것으로 판단된다.

• 한국수산과학회지
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• 제36권4호
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• pp.372-377
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• 2003

Feeding habits of juvenile Liparis tanakai collected from the eelgrass bed in Kwangyang Bay were studied. L. tanakai (2.0-6.0 cm SL) was a carnivore which consumed mainly amphipods (caprellids and gammarids) and caridean shrimps. Its diets also included a large amount of copepods, polychaetes and small fishes. Three distinct ontogenetic feeding groups were noted: (1) the individuals of 2.0-2.5 cm SL preyed heavily on copepods, (2) individuals of 2.5-4.0 cm SL fed mainly on amphipods. (3) individuals over 4.0 cm SL preyed mainly on caridean shrimps and small fishes. The dietary breadth of each size class showed relatively low value, and this means that juvenile L. tanakai depends on only few kinds of food organisms.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.82-87
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• 1994

Signal transduction through G protein-coupled receptors comprises three functional components, a receptor, a G protcin and a effector protein. Work over the last sevcral ycars has led to the characterization or virtually all of the components or these systems. what has come out or those studies is that these mechanisms of signal transduction are pervasive in nature being found in mammalian and avian species, as well as lower organisms such as yeast and slime mold. It is known that G protein-coupled receptors mediate the action of such diverse molecules such as small hormones and neurotransmitters, small peptide molecules as well as glycoprotein hormones and various sensory perceptions such as light, olfaction and most likely taste.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권3호
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• pp.273-276
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• 2006

RNA interference (RNAi), a process of sequence-specific gene suppression, has been known as a natural gene regulatory mechanism in a wide range of lower organisms. Recently, we have reported that a transfection of human U6 promoter (hU6) driven hairpin small-interference RNA (siRNA) plasmid specifically knocks down the target gene by post-transcriptional gene silencing in mammalian cells. Here we report that transfection of polymerase chain reaction (PCR) products, containing human U6 promoter with hairpin siRNA, knocks down the target gene expression in human teratocarcinoma NT-2/D1 cells. Moreover, we showed 3' end termination sequence, 5 Ts, is not critical elements for knocking down in PCR-based siRNA system. Therefore, the PCR-based siRNA system is a promising tool not only for the screening but also to temporally regulate gene expression in the human progenitor cells.

• 한국가금학회지
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• 제43권4호
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• pp.243-251
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• 2016

Chicken not only serves as a high-protein source to humans, but it is also used as a suitable biomodel for increasing livestock productivity and studying human diseases. Chickens have numerous advantages as model organisms mainly because of they are relatively convenient to manage due to their small body size and short generational interval. In addition, they have a small genome size and numerous genes have biologically similar functions to those of human and livestock animals. In this review, we investigated the chicken biomodel for human disease research and the use of this model for increasing livestock productivity. This summary could provide useful and basic information for further development of strategies for enhancing livestock production and human disease studies.

• BMB Reports
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• 제55권11호
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• pp.535-540
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• 2022

Ribosomes, acting as the cellular factories for protein production, are essential for all living organisms. Ribosomes are composed of both proteins and RNAs and are established through the coordination of several steps, including transcription, maturation of ribosomal RNA (rRNA), and assembly of ribosomal proteins. In particular, diverse factors required for ribosome biogenesis, such as transcription factors, small nucleolar RNA (snoRNA)-associated proteins, and assembly factors, are tightly regulated by various post-translational modifications. Among these modifications, small ubiquitin-related modifier (SUMO) targets lots of proteins required for gene expression of ribosomal proteins, rRNA, and snoRNAs, rRNA processing, and ribosome assembly. The tight control of SUMOylation affects functions and locations of substrates. This review summarizes current studies and recent progress of SUMOylation-mediated regulation of ribosome biogenesis.

• 한국수산과학회지
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• 제26권6호
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• pp.511-518
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• 1993

해산어류의 종묘생산시 초기 동물먹이생물로 널리 이용되는 미소형, 소형, 대형 윤충(Brachionus plicatilis)의 환경요인에 따른 수명과 번식력을 조사하였다. 전반적으로 온도는 $25{\sim}27^{\circ}C$가 $20{\sim}22^{\circ}C$ 보다 번식력과 수명이 높았으며 미소형과 소형윤충은 이러한 현상이 더욱 뚜렷하였다. 염분은 미소형과 대형 윤충은 32ppt보다 16ppt에서 번식력이 더욱 높았던 반면 소형 윤충은 32ppt에서 더욱 높았다. 먹이생물은 미소형과 대형 윤충은 Tetraselmis tetrathele 소형 윤충은 Chlorella ellipsoidea가 더 좋은 먹이 효율을 보였다. 각 윤충의 먹이생물, 수온, 염분에 따른 최고의 번식력은 미소형 윤충은 Tetraselmis tetrathele, $25{\sim}27^{\circ}C$, 16ppt, 소형 윤충은 Chlorella ellipsoidea, $25{\sim}27^{\circ}C$, 32ppt ,대형 윤충은 Chlorella ellipsoidea, $25{\sim}27^{\circ}C$, 16ppt에서 나타났다.