• Title/Summary/Keyword: Parallel culture

Search Result 170, Processing Time 0.037 seconds

A Study on Seedling Production of Jicon Scallop, Chlamys farreri 1. Spawning, Development and Rearing of Larvae (비단가리비 종묘생산을 위한 연구 1. 산란, 발생 및 유생사육)

  • Na Gui-Hwan;Jeong Woo-Geon;Cho Chang-Hwan
    • Journal of Aquaculture
    • /
    • v.8 no.4
    • /
    • pp.307-316
    • /
    • 1995
  • Jicon scallop (Chlamys farreri), as one of new culture species, has been taken a growing interest in Korea recently. Artificial seeds are needed since seeds in natural waters are absolutely short. To develop the better methods for the artificial spawning and the rearing larvae on a large scale, experiments were carried out from July 1993 to May 1994. Mother shells were collected from the area near Tong-yeong and Geoje-do, the southern part of the Korean Penninsula. It was estimated that a period of 2-years was needed to be mother shells after the fertilization. Generally, spawning occourred intermittently from March to August and the maximum occurred in July. A best way for the artificial spawning was a chemical incentive, a 'serotonin injection' in parallel with the exposure and the temperature stimulation. Densities of the fertilized eggs for the normal development was from 30 to 40 per mililiter. It took 27-days from the fertilization to the settling larva averaging $155{\mu}m$ in size with water temperature 11.5\~13.0^{\circ}C$. Isochrysis galvana and Chaetoceros calcitrans with a density of $1,500\times10^4$ cells per ililiter were supplied for rearing the larvae. A proper density of larvae was 10 individuals per mililiter, and the survival rate of larvae from the flowing water system was much better than that of larvae from the still water.

  • PDF

Effect of Growth Hormone Releasing Hormone on the Proliferation of Cultured Cells Derived from Rat Anterior Pituitary Gland (배양중인 흰쥐 뇌하수체 전엽 세포의 증식에 미치는 Growth Hormone Releasing Hormone (GHRH)의 영향)

  • Lee, Sung-Ho
    • Development and Reproduction
    • /
    • v.4 no.2
    • /
    • pp.237-242
    • /
    • 2000
  • Growth hormone releasing hormone (GHRH), the major hypothalamic stimulus of GH secretion from the anterior pituitary gland, has been found to be present in several extrahypothalamic sites including placenta testis, ovary and anterior pituitary gland. The present study was performed to elucidate the role of pituitary GHRH on proliferation of cells derived from rat anterior pituitary gland. The GHRH content of pituitary tissue, cultured pituitary cells, and the conditioned media was evaluated by radioimmunoassay (RIA). Primary cultures of pituitary cells derived from adult rats were prepared by enzymatic dispersion. Significant amounts of GHRH-like molecules were detected in both pituitary tissue and cell cultures by GHRH RIA. Competition curves with increasing amounts of tissue extracts and conditioned media were parallel with those of standard peptide, indicating that the pituitary GHRH-like material is similar to authentic GHRH. To analyze specific cell types responsible for producing GHRH in anteroior pituitary, cell fractionation technique combined with GHRH RIA was performed. In cell fractionation experiment, the highest level of GHRH content was found in gonadotrope enriched-fraction and followed by somatotrope-, lactotrope- and thyrotrope-fraction. Treatment of pituitary cells with GHRH resulted in a dose-dependent increase in [$^3$H] thymidine incorporation. The mitogenic effect of GHRH could be mediated by typical oncogenic activation since the GHRH induced transient increase in c-fos mRNA levels with peak response at 30 minutes. The present study demonstrated that i) the pituitary GHRH expressed in the rat anterior pituitary gland can be secreted, ii) among the various cell types, gonadotropes and somatotorpes are the major GHRH source, and iii) the GHRH treatment increased the [$^3$H] thymidine incorporation and c-fos transcriptional activity in the pituitary cell culture. These findings suggested that GHRH could participated in the paracrine and/or autocrine regulation of cell proliferation, as well as promoting growth hormone secretion.

  • PDF

A Study on Public Library Finance (공공도서관의 재원확보에 관한 연구)

  • Suh Hye-ran
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.23
    • /
    • pp.263-301
    • /
    • 1992
  • In recent years, Korean public libraries, placed under changing circumstances, require that some new and positive financial policies be formulated for the improvement of their services. T he purpose of this study is to propose a scheme to ensure the revenues of Korean public libraries. The main contents of this study are as follows : (1) Public finance theory is applied to the question of why the public library is publicly supported. The public library does not contribute to stabilization, but it does playa role in each of the other public sector functions : allocation of resources and redistribution of income. In public finance terms there is justification for at least partial subsidy of public library services, which have the attributes of public goods, merit goods and externalities. (2) Public libraries in Korea find themselves suffering from limited budgets. They are neglected in national and local budgets. The lack of adequate funding for library collections prevents libraries from rendering efficient services. (3) In order to put the finances of the Korean public library system on a firm basis, the following proposals are made: 1) It is proposed that the parallel administration under which public libraries are organized be unified to be directly under the local governments. 2) It is proposed that the legislative and administrative system for public library finance be strengthened. (1) Library expenses should be itemized independently in the calculation of general grants-in-aid to local governments. (2) A fixed portion of the total municipal revenue should be appropriated for public library services. It can be executed by making provisions expressly in the annual guidelines for budgeting, municipal ordinances, or in the Library Promotion Law. The rate of allocation should be specified as a part of the national public library development plan. (3) Library tax as a local tax can be imposed. An indirect tax is preferable in order to avoid public misunderstanding and antagonism. 3) The augmentation of the specific grants-in-aid for the public library is proposed. The Library Promotion Law and the Law on Budget and Administration of Grants should be amended to oblige the central government to give financial assistance to local public libraries. 4) It is proposed that strategies to encourage private endowments be worked out. Revision of the Law on Tax Reduction and Exemption and the activation of an advisory library committee at each public library are recommended. 5) Funding and utilization of the envisioned Library Promotion Foundation is proposed. Government contributions, contributions from the Culture and Arts Foundation, and donations from individuals, corporations, and enterprises can be considered as the financial resources of the Foundation. 6) It is proposed that the structure of the Korean Library Association be consolidated to exercise greater influence over the formation of national policy on the public library system. 7) It is proposed as an ultimate guarantee of the health of the public libraries that the citizenry be educated to strongly support library services in responce to the active services provided by the public libraries.

  • PDF

A Matter of Professionalism: Academic Misconduct of Veterinary Students (수의전문직업성 측면에서 본 수의과대학 학생의 학습윤리)

  • Chun, Myung-Sun;Ryu, Pan-Dong;Yoon, Junghee
    • Journal of Veterinary Clinics
    • /
    • v.32 no.2
    • /
    • pp.174-179
    • /
    • 2015
  • Academic integrity guarantees the professional integrity and validity of the education and qualifications offered by the veterinary schools. In this study, we analyzed the responses of 528 veterinary students of two veterinary schools in Seoul regarding their awareness about, knowledge of, and frequency of engaging in academic misconduct. A total of 88.4 percent of the participants agreed that cheating and plagiarism by undergraduates would influence their future academic misconduct. The most common form of academic misconduct was plagiarism (71.7% in the A school, 69.5% in the B school), with falsification (40.2% in the A school, 31.7% in the B school) also reported at a high rate. Students indicated the lack of a culture of academic integrity as the main reason for academic misconduct. According to the regression analysis students' awareness and knowledge of academic integrity and their perception of peers' academic misconduct predicted a significant amount of variance of the frequency of academic misconduct. The findings of this study support that academic integrity should be learned in a flexible format from an early stage of professional development in veterinary curriculum. In parallel with the efforts of faculty, a community approach may be likely to improve the academic environment in terms of integrity.

Effects of High Glucose on Na,K-ATPase and Na/glucose Cotransporter Activity in Primary Rabbit Kidney Proximal Tubule Cells

  • Han, Ho-Jae
    • The Korean Journal of Physiology
    • /
    • v.29 no.1
    • /
    • pp.69-80
    • /
    • 1995
  • Renal proximal tubular hypertrophy and hyperfunction are known to be early manifestations of experimental and human diabetes. As the hypertrophy and hyperfunction have been suggested to be central components in the progression to renal failure, an understanding of their underlying causes is potentially important for the development of therapy. A primary rabbit kidney proximal tubule cell culture system was utilized to evaluate the possibility that the renal proximal tubular hypertrophy and hyperfunction observed in vivo in diabetes mellitus, can be attributed to effects of elevated glucose levels on membrane transport systems. Primary cultures of rabbit proximal tubules, which achieved confluence at 10 days, exhibited brush-border characteristics typical of proximal tubular cells. Northern analysis indicated $2.2{\sim}2.3$ and 2.0 kb Na/glucose cotransporter RNA species appeared in fresh and cultured proximal tubule cells after confluence, repectively. The cultured cells showed reduced Na/glucose cotransporter activity compared to fresh proximal tubules. Primary cultured proximal tubule cells incubated in medium containing 20 mM glucose have reduced ${\alpha}-MG$ transport compared to cells grown in 5 mM glucose. In the proximal tubule cultures incubated in medium containing 5 mM or 20 mM glucose, phlorizin at 0.5 mM inhibited 0.5 mM ${\alpha}-MG$ uptake by 84.35% or 91.85%, respectively. The uptake of 0.5 mM ${\alpha}-MG$ was similarly inhibited by 0.1 mM ouabain (41.97% or 48.03% inhibition was observed, respectively). In addition, ${\alpha}-MG$ uptake was inhibited to a greater extent when $Na^{+}$ was omitted from the uptake buffer (81.86% or 86.73% inhibition was observed, respectively). In cell homogenates derived from the primary cells grown in 5 mM glucose medium, the specific activity of the Na/K-ATPase $(6.17{\pm}1.27\;{\mu}mole\;Pi/mg\;protein/hr)$ was 1.56 fold lower than the values in cell homogenates treated with 360 mg/dl D-glucose, 20 mM $(9.67{\pm}1.22\;{\mu}mole\;Pi/mg\;protein/hr)$. Total $Rb^{+}$ uptake occurred at a significantly higher rate (1.60 fold increase) in primary cultured rabbit kidney proximal tubule cell monolayers incubated in 20 mM glucose medium $(10.48{\pm}2.45\;nM/mg\;protein/min)$ as compared with parallel cultures in 5 mM glucose medium. $Rb^{+}$ uptake rate in 5 mM glucose medium was reduced by 28% when the cultures were incubated with 1 mM ouabain. The increase of the $Rb^{+}$ uptake by rabbit kidney proximal tubule cells in 20 mM glucose could be attributed primarily to an increase in the rate of ouabain-sensitive $Rb^{+}$ uptake $(5\;mM\;to\;20\;mM;\;4.68{\pm}0.85\;to\;8.38{\pm}1.37\;nM/mg\;protein/min)$. In conclusion, the activity of the renal proximal tubular Na,K-ATPase is elevated in high glucose concentration. In contrast, the activity of the Nafglucose cotransport system is inhibited.

  • PDF

Biosynthesis and Degradation of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in Alcaligenes sp. SH-69 (Alcaligenes sp. SH-69에서의 Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) 생합성 및 분해)

  • Ryu, Kang-Eun;Choi, Gang Guk;Park, Sang Kyu;Kim, YoungBaek;Rhee, Young Ha
    • Korean Journal of Microbiology
    • /
    • v.34 no.4
    • /
    • pp.219-224
    • /
    • 1998
  • The cyclic metabolism of poly(3-hydroxyhutyrate-co-3-hydroxyvalerate) synthesized from glucose by Alcaligenes sp. SH-69 in the presence or absence of new carbon substrate was investigated. In batch culture, the content and weight average molecular weight of the copolymer already stored in the cell decreased rapidly when there was no other carbon source available. After the depletion of carbon source, the amount of high molecular weight copolymer decreased more rapidly than that of low molecular weight copolymer, and as a result, average molecular weight distribution shifted to the lower value. The addition of a mixture of glucose and levulinic acid when the initial carbon substrate, glucose, was nearly depleted supported the continual increase in cell mass and the accumulation of poly(3HB-co-3HV) with high molar fraction of 3HV. However, solvent fractionation of the polymer with acetone revealed the degradation of pre-existing polyhydroxyalkanoale (PHA) in parallel with the synthesis of PHA from new carbon substrate. Even though PHAs obtained from each substrate alone were the copolymer of 3HB and 3HV, it was found that the polymer accumulated in the cells grown by sequential feeding was mainly physical mixture of two poly(3HB-co-3HV) copolymers containing different molar fractions of 3HV.

  • PDF

The Poet Kim Shi-Jong living in both Joseon and Japan: the Meaning of 'Zainichi' Expressed in Epic Poem Niigata (조선과 일본에 사는 시인 김시종 - 장편시집 『니이가타』에 표현된 '재일'의 의미)

  • Kim, Gae-Ja
    • Cross-Cultural Studies
    • /
    • v.45
    • /
    • pp.7-32
    • /
    • 2016
  • This article considers the meaning of 'Zainichi (在日)' expressed in epic poem Niigata (1970) written by Korean-Japanese poet Kim Shi Jong. Kim sets two points in his creation of poetry. One is summer of liberation released from Japanese colonial domination in 1945. The other is Japan where he lives as a Korean-Japanese. These two points have made him think about the meaning of living in post-colonial era and the national division of Korea, his home country. His thought like this is well expressed in his epic Niigata. Niigata was written in 1959 when the ship returning to North Korea departed from Niigata of Japan. However, Kim couldn't return to his home country at that time. He stowed away from South Korea to Japan in 1949. He participated in antigovernment activities occurred in Jeju Island to block the national division between the south and the north after the liberation in 1945, the so-called 4.3 incident. Besides, he was having conflict with the organization of North Korea at that time because it required a doctrinaire belief and creation in Korean. Kim was writing poems in Japanese and pursued the life of existence as a Korean-Japanese. Therefore, he decided to remain in Japan instead of returning to North Korea. Of course, he could not return to South Korea because he was a refugee. Kim imagined in Niigata, the place located in an extension of the 38th parallel and the spot of national division. He could not cross the division line when he was in his home country, but he could do it in Niigata through imagination. The life as a Korean-Japanese makes it possible. 'Zainichi', which means living in Japan, has been recognized as a worse situation compared to living in Korea. However, Kim changed his way of thinking. Zainichi can embrace South Korea, North Korea, and Japan. This is the very reason why he lives there as a Korean-Japanese. His thought like this is well expressed by symbolic representations and metamorphose as well as the imagination of spatial extension.

Evaluation and Forecast of North Korea's Nuclear Policy through Libya Model (리비아 모델을 통한 북한의 핵 정책 평가와 전망)

  • Han, Seung Jo;Shin, Jin
    • Convergence Security Journal
    • /
    • v.18 no.3
    • /
    • pp.113-122
    • /
    • 2018
  • The issue of security on the Korean peninsula is facing the greatest upheaval in 2018 with the inter-Korean summit and the US-North Korea summit. North Korea has pursued the parallel policy developing military and economic at the same time. However, North Korea is changing its route to give up nuclear weapons and focus on the economy through summit talks. Since the change in North Korea is similar to that of Libya in the past, it is necessary to analyze why North Korea is trying to abandon its nuclear program and how the process is flowing compared to the case of Libya. The Libya model was constructed and analyzed in terms of international and domestic perpectives and recognition of the situation by leadership. North Korea's nuclear policy was evaluated based on the Libya model. The nuclear development of Libya and North Korea has caused diplomatic and economic pressures from the international community and ultimately led to instability of the regime. Two countries have tried to abandon nuclear program in order to solve the instability of the regime, also gain the economic reward insead. Libya took economic benefits and secured some of the stability of the regime, but the regime collapsed under the wave of democracy due to the influx of foreign capital and ideas. North Korea will seek diplomatic and economic gains with the example of Libya, but will try to limit as much as possible the culture of democracy and the full opening that can be incidental.

  • PDF

A Command of French and anti-style used in Lee Sang's poetic work (이상(Lee Sang)의 시작품에 구사되는 프랑스어와 반문체)

  • Lee, Byung Soo
    • Cross-Cultural Studies
    • /
    • v.49
    • /
    • pp.229-248
    • /
    • 2017
  • This paper is a study on French of Lee Sang's poems called metaphysical scandals in Korean poetry. Is poetic language he used a common poetic word or a non-poetic word in French? What kind of harmony do words and sentences composed of French have with Korean, Chinese character, and non-poetic word? Based on these questions, we analyzed a command of French, that is symbolic, geometrical, and pictorial French as well as repetitive and parallel constitution used in form of words and sentences. In Lee Sang's poems, as a result, the use of French is seen as a mixture of non-poetic word. It shows characteristics that reject traditional native language and the creation of poetry. In his poems, French is also an important factor of avant-garde poetic material and experimental creation technique. In his poems, French is used as a special tool to express internal conflicts of the poet. Lee Sang showed experimental style that could not be found in modern Korean literature by using signifier and signifed that french language has.

The Safety Management Status and Policy Directions for Sports Facilities in Gangwon Province (강원도 체육시설 안전관리 실태와 정책방향)

  • Kim, Tae-Dong;Kim, Heung-Tae
    • Journal of Korea Entertainment Industry Association
    • /
    • v.14 no.4
    • /
    • pp.265-288
    • /
    • 2020
  • Public sports facilities, which have increased in number due to continued government attention and investment, are used by a large number of residents in the province. However, the safety management in some facilities is limited due to being carried out with reference to safety management standard manuals as a mere formality. The purpose of this study was to analyze the current safety management status of public sports facilities in Gangwon and to seek out a policy direction that can be used safely by provincial residents. To this end. the study made a comprehensive review of central government and Gangwon government policy trends in sports facility safety management in Gangwon along with actual cases, from which it made the following suggestions for policy directions. First, it proposed the designation and operation of specialized institutions using locally established development and municipal companeie,. universities and cooperatives. and the training and fostering of safety managers for sports facilities. Secod, it proposed the establishment of a foundation to promote a sport facility safety culture such as designation of and commendation for excellent facility safety management on the provincial level. holding case presentations on safety and responsiveness. sports safety experience plazas, sports safety classes, and cartoons for public relations. Third, it proposed setting the foundation for a safety management system that takes into account the greater quantity of leisure sports facilities compared to other cities and provinces. Fourth, it proposed the establishment of an institutional basis to establish support ordinance for sports facility safety management that meets the local conditions in Gangwon. Fifth, it proposed safety management measures for sports facilities at the central government level in parallel with a basic plan for sports facility safety management tailored to Gangwon that matches the conditions on the ground in the region.