• Animal cells and systems
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• 제14권4호
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• pp.315-322
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• 2010

We studied and compared the age structure, body size, and growth rates of field populations of two Korean salamander species (Hynobius yangi and Hynobius quelpaertensis) to elucidate important aspects of basic population dynamics of these two endemic Hynobius species. In both populations, females were sexually mature at three years of age, while H. yangi and H. quelpaertensis males matured at two and three years of age, respectively. Both males and females of H. yangi and H. quelpaertensis attained a maximum age of 11 years and 10 years, respectively. In both species, the snout-vent length (SVL) and body weight (BW) of the females were greater than those of the males. The SVL, BW, and asymptotic SVL of both male and female H. yangi were smaller than those of H. quelpaertensis. The adult growth rates after sexual maturation of male and female H. yangi were lower than those of H. quelpaertensis, possibly resulting in the smaller body size of the former, although overall growth coefficients were not significantly different between the two species. We also compared the age structure and growth rates of three Korean and three Japanese species of Hynobius.

• 한국응용곤충학회지
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• 제37권2호
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• pp.127-135
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• 1998

담배나방의 월동생태를 규명하기 위하여 휴면 유기시기에 지역별로 유충을 채집하여 휴면용을 얻은후 수원과 진주등에 묻고 월동용의 생존욜과 발육기간을 조사하였다. 휴면용의 월동 중 생존육은 5%미만으로 매우 낮은 반면, 인공사육용기에 담아서 흙에 묻었을 경우 60%이상의 높은 생존율을 나타냈다. $25^{\circ}C$ 항온조건에서 발육기간은 지역이나 시험연도 또는 보관환경에 따라 20.4일에서는 43.9일로 개체간 변이가 컸다. 월동양상은 30일 이내에 우화하는 개체들과 30일이상 걸리는 개체로 구분할 수 있었으며 30일 이상인 개체의 비율은 중부지방이 남부지방보다 높았다. 반면 중부지방에서 채칩한 개체를 남부지역인 진주 야외조건에 보관할 경우 그 비율은 감소하는 경향을 보였다.

• 한국동물학회지
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• 제13권1호
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• pp.3-8
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• 1970

경기도 파주지역의 밤나무숲은 밤나무혹벌(Dryocosmus kuriphilus Yasumatsu)이 1965년 이래로 번성하여 막심한 피해를 받고 있으며 벌목되는 나무의 수가 증가 되어가는 실정이다. 저자는 밤나무혹벌의 생물학적 자연구제의 대책을 연구코저 파주군의 법원리, 마장리, 분수리의 3개처와 양주군의 보광사, 벽제리, 2개처에 대하여 밤나무숲의 곤충상을 조사하였다. 전 지역에 대하여 5목 35종의 곤충을 채집하였으며 법원리에서는 해충의 번성이 심하였으나 분수리에서는 작년가지에 많은 밤나무혹벌의 혹이 금년가지에서는 볼수 없어 하나의 회복증상을 발견하고 그 이유로서 법원리는 숲이 고립되어 있으나 분수리는 상수리나무숲으로 잘 둘러싸여 있다는 사실을 지적, 삼림조성에 있어서의 혼합림조성 방식을 제창하였다.

• Animal cells and systems
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• 제16권4호
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• pp.329-336
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• 2012

This study evaluated ecological health, using various biomarkers and bioindicators, of pale chub (Zacco platypus) as a sentinel species, in Daejeon Stream, South Korea, during AprilMay 2011. The biomarkers and bioindicators were compared among three sites of control: Reference ($C_z$), transition ($T_z$), and the urban zones ($U_z$); and the 7-Ethoxyresorufin-O-deethylase (EROD) activity, DNA damage, acetylcholinesterase (AChE) activity, and vitellogenin (VTG) concentrations were more significantly increased in the $U_z$ than in the $C_z$. Also, physiological markers such as condition factor, liver somatic index, visceral somatic index, and gonad somatic index were significantly increased in the $U_z$ than in the $C_z$. For the health assessments, three categorized parameters of blood chemistry, molecular biomarkers, and physiological bioindicators were standardized and calculated as a star-plot, representing values of Integrated Health Response (IHR). Values of IHR had more significant (P<0.05) increases in the $U_z$ than any other zones, indicating an impairment of ecological health by organic matter, nutrients (N, P), and toxic chemicals. This study is based on low levels of biological organization approach of molecular and physiological biomarkers and bioindicators, so further study of high-levels of biological organization approach such as community and population is required for overall range of health assessments. The approach of IHR values, however, may be useful in providing early warning of future impacts on ecological health.

• Archives of Pharmacal Research
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• 제21권4호
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• pp.398-405
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• 1998

We investigated the effects of triterpene acids (TAs), ursolic acid (UA) and oleanolic acid (OA), on the induction of proliferation and differentiation of normal rat mammary epithelial cells (RMEC) or organoids cultured in Matrigel or primary culture system. To elucidate the effects, we tested their differentiation inducing activities with intercellular communication ability, cell cycle patterns, induction of apoptosis, and morphological differentiation in the three dimensional extracellular culture system. To study the changes of RMEC subpopulation in culture, the cultured cells were isolated, immunostained with peanut lectin (PNA) and anti-Thy-1.1 antibody and then analyzed with flow cytometry. Four different subpopulations, such as PNA and Thy-1.1 negative cells (B-), PNA positive cells (PNA+), Thy-1.1 positive cells (Thy-1.1+), PNA and Thy-1.1 positive cells (B+), were obtained and the size of each subpopulation was changed in culture with time in the presence of TAs. Intercellular communication was observed in culture for 7 days in TAs-treated cells, but not in culture for 4 days with scrape-loading dye transfer technique. $G_2$/M phase cells and the number of apoptotic population were increased in TAs-treated groups in cell cycle analyses. S phase fractions were reduced and the change of $G_1$ phase cells was not observed. The colonies with distinct multicelfular structures, such as stellate, ductal, webbed, squamous, lobulo-ductal colonies, were observed in Matrigel culture and the frequencies of each colony were changed in the presence of TAs. These results suggest that UA and OA have differentiation inducing effects on rat mammary epithelial cells in primary or in Matrigel culture.

• 생명과학회지
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• 제25권4호
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• pp.369-375
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• 2015

식물 보존의 권고지역에서 식물 집단의 공간적 데이터는 여러 목적에서 중요하다. 부산광역시 금정산과 아홉산 의 대사초(Carex siderosticta)의 지리적 거리에 따른 공간적 분포를 분석하였다. 공간적 양상의 분석 방법은 여러 패치 척도, 분산 척도에 의거한 plot(플롯)의 크기에 따라 집단의 균질성 또는 운집을 분석하였다. 대사초의 많은 자연 플롯은 산림군락에서 균질하지 않았다. 예를 들면 균질한 플롯은 6.0 m $\times$ 6.0 m 이내였다. 플롯의 크기가 6.0 m $\times$ 12.0 m 이상이면 운집되었다. 대사초의 이웃 패치는 평균 7.5 m에서 9.0 m사이였다. 그런데 자연집단이 인간의 활동에 의해 교란되면 운집은 9.0 m보다 짧은 거리에서 일어났다. 결론적으로 대사초의 지리적 분포는 플롯의 밀도에 균질하지 않았고 금정산과 아홉산 집단에서 집단 크기에 따라 다르며 인간의 간섭은 플롯에서 밀도 효과를 일으킨다.

• Molecules and Cells
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• 제39권6호
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• pp.501-507
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• 2016

The corpus callosum is a bundle of nerve fibers that connects the two cerebral hemispheres and is essential for coordinated transmission of information between them. Disruption of early stages of callosal development can cause agenesis of the corpus callosum (AgCC), including both complete and partial callosal absence, causing mild to severe cognitive impairment. Despite extensive studies, the etiology of AgCC remains to be clarified due to the complicated mechanism involved in generating AgCC. The biological function of PI3K signaling including phosphatidylinositol-3,4,5-trisphosphate is well established in diverse biochemical processes including axon and dendrite morphogenesis, but the function of the closely related phosphatidylinositol-3,4,-bisphosphate (PI(3,4)P2) signaling, particularly in the nervous system, is largely unknown. Here, we provide the first report on the role of inositol polyphosphate 4-phosphatase II (INPP4B), a PI(3,4)P2 metabolizing 4-phosphatase in the regulation of callosal axon formation. Depleting INPP4B by in utero electroporation suppressed medially directed callosal axon formation. Moreover, depletion of INPP4B significantly attenuated formation of Satb2-positive pyramidal neurons and axon polarization in cortical neurons during cortical development. Taken together, these data suggest that INPP4B plays a role in the regulating callosal axon formation by controlling axon polarization and the Satb2-positive pyramidal neuron population. Dysregulation of INPP4B during cortical development may be implicated in the generation of partial AgCC.

• 대한치과기공학회지
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• 제34권3호
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• pp.283-290
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• 2012

Purpose: This study was aimed to know the perception about Certified Dental Technician system of students majoring in dental laboratory technology in Korea. Methods: A survey was conducted for four months from August through November 2011 with questionnaires. The responses from 1148 students majoring in dental laboratory technology in Korea were analyzed with SPSS 12.0 program, and frequency analysis and chi square test were implemented. Results: Total students who responded to the questionnaire were 1148 (100%). The population characteristic of this survey is that 691 (60.2%) are male. The respondents believed that the job skill could be expanded by implementing the system (85.6%). Also, they responded that they would be willing to acquire the Certified Dental Technician qualifications in the future (95.5%). Conclusion: Students majoring in dental laboratory technology in Korea believed that the execution of the system of Certified Dental Technician would expand the dental technology industry.

• Journal of Microbiology and Biotechnology
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• 제22권12호
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• pp.1613-1620
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• 2012

Bacterial wilt caused by Ralstonia solanacearum is a devastating disease of many economically important crops. Since there is no promising control strategy for bacterial wilt, phage therapy could be adopted using virulent phages. We used phage PE204 as a model lytic bacteriophage to investigate its biocontrol potential for bacterial wilt on tomato plants. The phage PE204 has a short-tailed icosahedral structure and double-stranded DNA genome similar to that of the members of Podoviridae. PE204 is stable under a wide range of temperature and pH, and is also stable in the presence of the surfactant Silwet L-77. An artificial soil microcosm (ASM) to study phage stability in soil was adopted to investigate phage viability under a controlled system. Whereas phage showed less stability under elevated temperature in the ASM, the presence of host bacteria helped to maintain a stable phage population. Simultaneous treatment of phage PE204 at $10^8$ PFU/ml with R. solanacearum on tomato rhizosphere completely inhibited bacterial wilt occurrence, and amendment of Silwet L-77 at 0.1% to the phage suspension did not impair the disease control activity of PE204. The biocontrol activities of phage PE204 application onto tomato rhizosphere before or after R. solanacearum inoculation were also investigated. Whereas pretreatment with the phage was not effective in the control of bacterial wilt, post-treatment of PE204 delayed bacterial wilt development. Our results suggested that appropriate application of lytic phages to the plant root system with a surfactant such as Silwet L-77 could be used to control the bacterial wilt of crops.

• 한국미생물·생명공학회지
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• 제48권2호
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• pp.230-235
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• 2020

The global evolution of antibiotic resistance has threatened the efficacy of available treatment options with ravaging impacts observed in developing countries. As a result, investigations into the prevalence of antibiotic resistance and the role of plasmids are crucial. In this study, we investigated the presence and distribution of bla_TEM and gyrA genes, plasmid profiles, and the antimicrobial susceptibility pattern of Salmonella strains isolated from raw meat and stool sources across Niger State, Nigeria. Ninety-eight samples, comprising 72 raw meat and 26 stool samples, were screened for Salmonella spp. The antimicrobial susceptibility of Salmonella isolates to 10 commonly used antimicrobial agents was determined using the KirbyBauer disc diffusion method. Isolates were further analyzed for plasmids, in addition to PCR amplification of beta-lactamase (bla_TEM) and gyrA genes. A total of 31 Salmonella spp. were isolated, with 22 from raw meat (70.97%) and 9 from stool (29.03%). Salmonella spp. with multiple resistance patterns to ceftazidime, cefuroxime, ceftriaxone, erythromycin, ampicillin, cloxacillin, and gentamicin were detected. Ofloxacin and ciprofloxacin were found to be the most effective among the antibiotics tested, with 67.7% and 93.5% susceptible isolates, respectively. Nine (29.03%) isolates harbored plasmids with molecular sizes ranging between 6557 bp and 23137 bp. PCR amplification of gyrA was detected in 1 (3.23%) of the 31 isolates while 28 isolates (90.32%) were positive for bla_TEM. This study shows the incidence of antibiotic resistance in Salmonella isolates and the possible role of plasmids; it also highlights the prevalence of ampicillin resistance in this local population.