• 한국응용곤충학회지
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• 제57권3호
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• pp.191-197
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• 2018

중기문응애목 떠돌이응애과는 토양에 서식하는 포식성 응애로, 토양해충의 생물적 방제원으로 이용가치가 있다. 우리나라의 떠돌이응애과는 10속, 24종이 보고 되었다. 본 연구는 제주도 한라산천연보호구역 물장오리오름에서 토양응애 생물다양성 연구 중 이끼에서 우리나라 미기록종 Asca bicornis Canestrini & Fanzago, 1877을 발견하여 보고하는 바이다. 등판과 배판의 묘사를 통해서 형태적인 특징을 자세히 제공하였다. 근연종인 A. aphidioides는 등판 양쪽 말단에 돌출된 혹에서 각 1개의 센털이 있으나, A. bicornis는 2개가 나 있다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.224-224
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• 2017

In plants, cysteine(Cys) is decisive for protein and glutathione that acts as an indispensable sulfur grantor for methionine and many other sulfur containing secondary products. Cys formation is involved in the consecutive two reactions using two enzymes-serine acetyl transferase (SAT) and O-acetylserine (thiol)lyase (OASTL) and appeared in plant cytosol, chloroplast and mitochondria. OASTL is able to produce mimosine with 3-hydroxy-4-pyridone (3H4P) in lieu of $H_2S$ for Cys. In this report, we describe the first time cloning, purification and characterization of cytosolic(cy)OASTL from M. pudica and its expression in Escherichia coli and try to find out the cross link between this OASTL and the mimosine formation and to elucidate the metabolic role of cy-OASTL in M. pudica. The purified recombinant protein was 34.7 KDa. The optimum reaction pH and temperature was 6.5 and $50^{\circ}C$, respectively. The Michaelis constant (Km) and the Vmax value of the enzyme was $252{\pm}25{\mu}M$ and $57{\pm}3{\mu}M\;cysteine\;min^{-1}\;{\mu}g\;protein^{-1}$ for sulfide and $159{\pm}21{\mu}M$ and $58{\pm}2.4{\mu}M\;cysteine\;min^{-1}\;{\mu}g\;protein^{-1}$ for OAS subsequently. After cleaving the His-tag, we tried to observe cy-OASTL to form mimosine with appropriate substrate but it was not successful. It may be concluded that cy-OASTL of the present study is only Cys specific, not mimosine.

• Journal of Ecology and Environment
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• 제38권2호
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• pp.241-247
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• 2015

A participatory approach of local stakeholders is important to create a balance between nature protection and the sustainable use of natural resources in a nature reserve and its vicinity area. The zoning and management policy of biosphere reserves (BRs) is a good example of this idea, especially for island reserves. Yakushima was inscribed as a World Natural Heritage (WH) in 1993. Almost all of its residents did not remember that Yakushima was a BR. In addition, Yakushima has some problems in nature reserve management. Overabundance of the deer population is a critical threat to both agriculture and natural vegetation in the world heritage site. There are too many tourists visiting the WH site and Nagata-hama beach. The beach is a Ramsar site and one of the most important spawning grounds of sea turtles in the north Pacific. Now, residents and the municipality have decided to reactivate the Yakushima BR. Although the Ministry of the Environment of Japan has an initiative to manage the WH and the Ramsar site, the BR is managed by the municipality and local stakeholders. Local activities of both nature conservation and the sustainable use of natural resources are encouraged in the BR site. The islanders willingly included all areas of the island into the BR site. Scientists who have participated in the Society of Yakushimaology have played a significant role to build trust between local stakeholders and to seek feasible policies on the nature reserves. The concept of the "Yakushima Environmental Culture Village" is a good model for the extension plan of the Yakushima and Kuchinoerabujima BRs.

• Journal of Ecology and Environment
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• 제30권3호
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• pp.209-223
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• 2007

Twenty-four wetlands located in Higashi-Hiroshima City in West Japan were selected for this study in order to investigate both the relationship between aquatic plant composition and environmental conditions; and the relationship between changing land use patterns in the catchments and the concentration of different forms of nitrogen in the wetlands. The dominant and subdominant species which comprised the principal vegetation were determined based on a vegetation census conducted in each wetland during the growing season from June to August, 2006. The seasonal variations of water quality factors (pH, electrical conductivity, turbidity, dissolved oxygen, total dissolved solid, and temperature) and different forms of nitrogen such as nitrite, nitrate, ammonium, total nitrogen, dissolved organic nitrogen and dissolved inorganic nitrogen concentrations were analyzed as important indicators of water quality for the surface water of the wetlands. The surveyed wetlands were classified into three types (non-disturbed wetlands, moderately-disturbed wetlands and highly-disturbed wetlands), based on the degree of human disturbance to their catchment areas. An analysis of variance indicated that there was a significant difference among the wetland groups in the annual mean values of electrical conductivity, total dissolved solids, total nitrogen, nitrite, dissolved inorganic nitrogen and dissolved organic nitrogen. Classification of the wetlands into three groups has revealed a pattern of changes in the composition of plant species in the wetlands and a pattern of changes in nitrogen concentrations. A majority of the non-disturbed wetlands were characterized by Brasenia schrebi and Trapa bispinosa as dominant; with Potamogeton fryeri and Iris pesudacorus as sub-dominant species. For most of the moderately-disturbed wetlands, Brasenia schrebi were shown to be a dominant species; Elocheriss kuriguwai and Phragmites australis were observed as sub-dominant species. For a majority of the highly-disturbed wetlands, Typha latifolia and T. angustifolia were observed as dominant species, and Nymphea tetragona as the sub-dominant species in the study area. An analysis of land use and water quality factors indicated that forest area played a considerable role in reducing the concentration of nutrients, and can act as a sink for surface/subsurface nutrient inputs flowing into wetland water, anchor the soil, and lower erosion rates into wetlands.

• Animal Bioscience
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• 제34권12호
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• pp.1912-1920
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• 2021

Objective: This study investigated the effects of 5-aminolevulinic acid (5-ALA) on the motility parameters, mitochondrial membrane depolarization, and ATP levels in chicken sperm. Methods: The pooled semen from Barred Plymouth Rock males was used. In the first experiment, the semen was diluted 4-times with phosphate-buffered saline (PBS (-)) containing various concentrations (0, 0.01, 0.05, and 0.1 mM) of 5-ALA, and then the sperm motility parameters after incubation were evaluated by computer-assisted sperm analysis (CASA). In the second experiment, the semen was diluted 4-times with PBS (-) containing 0.05 mM 5-ALA, and then sperm mitochondrial membrane depolarization and ATP levels after 1.5 h of incubation were analyzed with the MitoPT^® JC-1 Assay and ATP Assay kits, respectively. In the third experiment, the semen was removed from the seminal plasma and resuspended with the mediums of PBS (-), PBS (-) supplemented with CaCl₂ and MgCl₂ (PBS (+)) + 5-ALA, PBS (+) + caffeine, and PBS (+) + caffeine + 5-ALA. Then, the sperm motility parameters after incubation were evaluated by CASA. In the last experiment, the semen was treated with the mediums of PBS (-), PBS (-) + 5-ALA, 5.7% glucose, 5.7% glucose + 5-ALA after removing the seminal plasma, and then the sperm motility parameters were evaluated by CASA. Results: The addition of 0.05 mM 5-ALA significantly increased the chicken sperm motility, progressive motility, linearity, average path velocity, curvilinear velocity, straight-line velocity, and the wobble. The sperm mitochondrial membrane depolarization was also increased by the 5-ALA treatment. The 5-ALA treatment decreased the sperm ATP levels. Both the caffeine treatment and glucose treatment decreased the sperm motility during incubation period. Conclusion: 5-ALA might increase sperm mitochondrial membrane depolarization to utilize the ATP for enhancing sperm movement.

• Nuclear Engineering and Technology
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• 제50권8호
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• pp.1324-1329
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• 2018

This study presents a practical application of complementary safety indicators, which can be applied in a safety assessment of a radioactive waste repository by excluding a biosphere simulation and comparing the artificial radiation originating from the repository with the background natural radiation. Complementary safety indicators (radiotoxicity flux from geosphere and radiotoxicity concentration in seawater) were applied in the safety assessment of a rock-cavern type low and intermediate level radioactive waste (LILW) repository in the Republic of Korea. The natural radionuclide ($^{40}K$, $^{226,228}Ra$, $^{232}Th$, and $^{234,235,238}U$) concentrations in the groundwater and seawater at the Gyeongju LILW repository site were measured. Based on the analyzed concentrations of natural radionuclides, the levels of natural radiation were determined to be $8.6{\times}10^{-5}$ - $8.0{\times}10^{-4}Sv/m^2/yr$ and $6.95{\times}10^{-5}Sv/m^3$ for radiotoxicity flux from the geosphere and radiotoxicity concentration in seawater, respectively. From simulation results obtained using a Goldsim-based safety assessment model, it was determined that the radiotoxicity of radionuclides released from the repository is lower than that of the natural radionuclides inherently present in the natural waters. The applicability of the complementary safety indicators to the safety case was discussed with regard to reduction of the uncertainty associated with biosphere simulations, and communication with the public.

• ALGAE
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• 제37권1호
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• pp.75-84
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• 2022

Intercellular nutrient and signal transduction are essential to sustaining multicellular organisms and maximizing the benefits of multicellularity. It has long been believed that red algal intercellular transport of macromolecules is prevented by the protein-rich pit plug within pit-connections, the only physical connection between cells. Fluorescein isothiocyanate-dextran and recombinant green fluorescence protein (rGFP) of various molecular sizes were injected into vegetative cells of Griffithsia monilis using a micromanipulator, and intercellular transport of the fluorescent probes was examined. Pit-connections were found to provide intercellular transport of tracers at rates comparable to plasmodesmata in other organisms. The time necessary for the transport to an adjacent cell was dependent on the molecular size and the direction of the transport. Fluorescent dextran of 3 kDa was transported to adjacent cells in 1-2 h after injection and migrated to all cells of the filament within 24 h, but fluorescent dextran of 10-20 kDa took 24 h to transfer to neighboring cells. The migration occurred faster towards adjacent reproductive cells and to apical cells than basally. Fluorescent tracers above 40 kDa and rGFP was not transported to neighboring cells, but accumulated near the pit plug. Our results suggest that pit-connections are conduit for macromolecules between neighboring cells and that these size-specific conduits allow intercellular communication between the vegetative cells of red algae.

• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4265-4271
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• 2022

Determination of ¹³⁷Cs, ⁴⁰K and ²¹⁰Po in water, bottom sediments and suspended matter of river systems of the Can Gio Biosphere Reserve, Vietnam was carried out. The average activity concentration of ¹³⁷Cs in waters of Ca Gau and Long Tau was 0.89 ± 0.14 and 1.08 ± 0.15 Bq m^-3 and was comparable to the levels of this radioisotope in waters of the East Sea. The activity concentration of ¹³⁷Cs in bottom sediments was 2.23 ± 0.81 and 3.63 ± 1.24 Bq kg^-1. The activity concentration of ¹³⁷Cs in water and bottom sediments could be characterized as low. So, the water areas of the Ca Gau and Long Tau rivers could be attributed to areas with insignificant pollution by technogenic radionuclides. The ²¹⁰Po activity concentration in bottom sediments of the Ca Gau and Long Tau rivers ranged from 9.2 ± 1.2 to 25.5 ± 2.1 Bq kg^-1, which is typical for river bottom sediments. Such values indicate the absence of anthropogenic enhancement of the entry of this radionuclide into the Can Gio river systems. The ⁴⁰K activity concentration varied within 467 ± 42-651 ± 39 Bq kg^-1 and represented typical values of potassium content in the bottom sediments of coastal water bodies, subject to a significant influence of the lithogenic component of suspended matter.

• 영어영문학
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• 제58권5호
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• pp.943-974
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• 2012

This paper aims to suggest the compromising vision of nature and technology as the solution to get out of the globally accelerated technology environment in Don DeLillo's Cosmopolis. This novel intends to emphasize on the importance of physical environment as a precondition for the survival of human. Eric wants to be a posthuman with the cybernetic idea, pursuing to be the digital self in a vast biosphere that integrates both the nature and the technology. His obsessive worship of technology through his quest for the futurity results in the effacement of the humanity and the insulation from the nature. Cosmopolis is DeLillo's first 9/11 novel, which describes a young-billionaire asset manager Eric's one-day life in New York in April 2000. Eric can be the third Twin Tower as a symbol of global economic hegemony. By the allusion of the 9/11 catastrophic event, it can be said that Eric's fall is caused by his hubris and avarice as a global capitalist. Crossing the 47th Street toward the West in his limousine, his journey is revealed as the environmental reflections on his desires to attain the futurity and transcendence by technology. This novel cautions that the abuse of technology can bring out the obsolescence and erasure of the humanity and the nature. DeLillo suggests that the best hope for the evolutionary possibility of posthuman can be realized through the correlation with nature and technology. This future-oriented novel warns that the excessive technology should not lead to the disappearance of community and humanity, and the separation of self and nature. It admonishes that they should not follow pseudo-cosmopolitanism as the greedy world citizens, devoting on the velocity of newest technology. This novel recommends that humans should be the world citizen of global ecosystem, making the ameliorative environment through the correlation with self/environment and technology/nature, and gardening the restorative biosphere and the younger planet.

• Journal of Microbiology
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• 제35권4호
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• pp.241-252
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• 1997

Polychlorodibenzofurans and polychlorodibenzo-pdioxins are among the most toxic xenobiotics released into the biosphere and the cause of significant public concern because of their apparent ubiquityalbeit at low levels- in food and environment. Several bacteria able to degrade nonchlorinated dioxin and dibenzofuran and in some cases to attack chlorinated analogues have recently been isolated. This opens up the possibility that bioremediation processes may ultimately be developed to eliminate these toxic compounds from contaminated sites. In this review we summarize current knowledge on the genetics and biochemistry of dioxin and dibenzofruan degradation by Sphingomonas sp. RW1, a gram-negative bacterium, and highlight the unusual nature of the genetic organization of these pathways.