• Development and Reproduction
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• v.16 no.3
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• pp.185-193
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• 2012

For the gonadal sex management of younger longtooth grouper (Epinephelus bruneus), this work investigated the timing and histological process of ovary differentiation and oocyte development of longtooth grouper larvae and juvenile. Specimens (from 1 to 365 DAH) were collected for gonadal histological study from June 2008 to August 2009. Rearing water temperature was ranged from 20 to $24^{\circ}C$. The primordial germ cells could be observed from 10 to 15 DAH, while undifferentiated gonad occurs from 20 to 50 DAH in longtooth grouper. The initial ovarian phase was 60 to 110 DAH with the formation of ovarian cavity and the increased in size of gonad. The ovarian phase started at 140 DAH with appearance of oogonia. The gonad at 365 DAH appeared to have full of oogonia and primary growth stage oocyte. Formation of ovarian cavity indicates that the ovarian differentiation beginning at 60 DAH in longtooth grouper. The gonads in longtooth grouper differentiated directly into ovaries in all fish examined.

• Journal of Aquaculture
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• v.8 no.3
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• pp.231-240
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• 1995

This study was conducted to examine early gonadogenesis by using a histological method for the appearance of primordial germ cells (PGCs), protrude of genital ridge, and formation of primitive gonads in diploid and triploid mud loach, Misgurnus mizolepis. The pattern of early gonadogenesis including appearance of PGCs, formation of genital ridge, and development of primitive gonad in both diploid and triploid were not different histologically. Characteristics of PGCs of triploid were also the same as those of diploid. However, gonadal length of diploid was significantly longer than that of triploid (P<0.05).

• Mycobiology
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• v.48 no.4
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• pp.263-275
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• 2020

Phlebopus spongiosus is a well-known edible ectomycorrhizal mushroom indigenous to southern Vietnam. The mushroom specimens collected from northern Thailand in this study were identified as P. spongiosus. This identification was based on morphological characteristics and the multi-gene phylogenetic analyses. Pure cultures were isolated and the relevant suitable mycelial growth conditions were investigated. The results indicated that the fungal mycelia grew well on L-modified Melin-Norkans, and Murashige and Skoog agar all of which were adjusted to a pH of 5.0 at 30 ℃. Sclerotia-like structures were observed on cultures. The ability of this mushroom to produce fruiting bodies in the absence of a host plant was determined by employing a bag cultivation method. Fungal mycelia completely covered the cultivation substrate after 90-95 days following inoculation of mushroom spawn. Under the mushroom house conditions, the highest amount of primordial formation was observed after 10-15 days at a casing with soil:vermiculite (1:1, v/v). The primordia developed into a mature stage within one week. Moreover, identification of the cultivated fruiting bodies was confirmed by both morphological and molecular methods. This is the first record of P. spongiosus found in Thailand and its ability to form fruiting bodies without a host plant.

• Publications of The Korean Astronomical Society
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• v.1 no.1
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• pp.21-37
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• 1984

The origin of five small satellites (1980 S1, 1980 S3, 1980 S26, 1980 S27 and 1980 S28) and F-ring of Saturn which were recently discovered inside the orbit of Mimas, is proposed in terms of the resonant effects by external satellites in the Saturnian primordial extended ring. From the calculations of resonance locations and strengths, the following conclusion could be derived. Assuming that present two objects 1980 S1 and 1980 S3 were originally a single object 1980 S1+S3, 1980 S1+S3 had been formed due to Enceladus' 2/1 resonance and 1980 S26 due to Mimas' 3/2 resonance at first and then 1980 S28. 1980 S27 and F-ring were formed in the next due to 1980 S1+S3's 8/7, 9/8 and 10/9 resonances, respectively.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.42.1-42.1
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• 2014

Neutrino science has received a boost of attention quite recently in cosmology, since the outstanding discovery in particle physics over the last decade that neutrinos are massive: pinpointing the neutrino masses is one of the greatest challenges in science today, at the cross-road between particle-physics, astrophysics, and cosmology. Cosmology offers a unique 'laboratory' with the best sensitivity to the neutrino mass, as primordial massive neutrinos comprise a small portion of the dark matter and are known to significantly alter structure formation. I will first introduce a new suite of state-of-the-art hydrodynamical simulations with cold dark matter, baryons and massive neutrinos, specifically targeted for modeling the low-density regions of the intergalactic medium as probed by the Lyman-Alpha forest at high-redshift. I will then present and discuss how these simulations are used to constrain the parameters of the LCDM cosmological model in presence of massive neutrinos, in combination with BOSS data and other cosmological probes, leading to the strongest bound to date on the total neutrino mass.

• Mycobiology
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• v.29 no.3
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• pp.135-141
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• 2001

Differential display of reverse transcription(DDRT)-PCR was conducted to have a profile of the differentially expressed genes during the formation of fruiting body of Lentinus edodes. The lines of L. edodes(ImHyup-1) employed were cultivated in the artificial blocks of sawdust, and the fruiting body was induced from the mycelia or the mass protruded from the brown surface of the sawdust blocks. RNAs were prepared from the four different developmental stages; mycelial, primordial, and stipes and pileus of fruiting body. The fragments of cDNA were synthesized from the combinations of the arbitrary primers and 3' one anchored Oligo-dT primer. Twelve combinations using the primers have been tested, and among them nineteen bands were identified as differentially expressed. Those genes were further analyzed by DNA sequencing and followed by homology search. Characterization of one clone was conducted as a preliminary data and more are under investigation.

• Development and Reproduction
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• v.25 no.3
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• pp.173-183
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• 2021

The incidence of infertility among individuals of reproductive age has been growing due to genetic and environmental factors, and considerable research efforts are focused on solving this issue. Ovarian development is an overly complex process in the body, involving the interaction between primordial germ cells and gonad somatic cells. However, follicles located in the center of the in vitro ovary are poorly formed owing to ovarian complexity, nutrient deficiency, and signaling deficiency. In the present study, we optimized methods for dissociating gonads and culture conditions for the in vitro generation of miniaturized ovaries. The gonads from embryos were dissociated into cell masses and cultured on a Transwell-COL membrane for 3-5 weeks. Approximately 12 follicles were present per in vitro ovary. We observed that miniaturized ovaries successfully matured to MII oocytes in vitro from 150 to 100 ㎛ gonad masses. This method will be useful for investigating follicle development and oocyte production.

• Journal of Ginseng Research
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• v.13 no.1
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• pp.79-83
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• 1989

This study was conducted to determine the effect of growth regulators, IBA, GA, and BA, on the adventitious bud formation, shoot differentiation, and inflorescence development in embryo culture of Korean ginseng. The adventitious bud formation and shoot differentiation were significantly promoted by application of a combination of 1 ma/l IBA and 5 mg/l GA. The adventitious buds had the primordial shoots and were differentiated as to plantlets. About 5 to 10 adventitious buds developed around the basal axis of the epicotyle of the ginseng embryo, and development of inflorescence was possible only after shoot differentiation. The MS medium supplemented with a combination of 3 mal 1 each of IBA, GA, and BA was most effective for in vitro inflorescence development, and the ratio of inflorescence formation was 18.4%.

• Journal of Mushroom
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• v.8 no.1
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• pp.16-21
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• 2010

Sparassis crispa(Cauliflower mushroom) was an edible mushroom that shows remarkably high contents of 1.3-${\beta}$-Dglucan compared to other edible mushroom. The mushroom was known to give high antitumor and immunology activated, and then this mushroom was recently cultivated in Japan and Korea. However, cultivation methods ware becoming kept in secret or patents by some companies with complicated procedures. And it was not established cultivation methods of Sparassis crispa up to now. This study was conducted to solve the problem by short-log cultivation method of Sparassis crispa. Some factors effecting on the mycelial growth and primordial formation of Sparassis crispa were investigated. We could produce the mushroom using short-woods of Larix leptolepis, Pinus densiflora, Pinus rigida and Quercus acutissima. We get to high yield fruit-body on short-log cultivaiton of Pinus rigida. And soaking for 8hours in water solution containing 5% uncooked yeast with short-wood of Pinus rigida. The optimal moisture content and temperature were 90~95% and $23{\sim}25^{\circ}C$, respectively.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.517-519
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• 2015

A large-scale neutral hydrogen ($H\small{I}$) ring serendipitously found in the Leo I galaxy group is 200 kpc in diameter with $M_{H\small{I}}{\sim}1.67{\times}10^9M_{\odot}$, unique in size in the Local Universe. It is still under debate where this $H\small{I}$ ring originated - whether it has formed out of the gas remaining after the formation of a galaxy group (primordial origin) or been stripped during galaxy-galaxy interactions (tidal origin). We are investigating the optical and $H\small{I}$ gas properties of the dwarf galaxies located within the gas ring in order to probe its formation mechanism. In this work, we present the photometric properties of the dwarfs inside the ring using the CFHT MegaCam $u^{\ast}$, $g^{\prime}$, $r^{\prime}$ and $i^{\prime}$-band data. We discuss the origin of the gas ring based on the stellar age and metal abundance of dwarf galaxies contained within it.