• Korean Journal of Animal Reproduction
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• v.21 no.3
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• pp.229-238
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• 1997

Chromosome condensation and swelling of the donor nucleus have been known as the early morphological indicators of chromatin remodelling after injection of a foreign nucleus into an enucleated recipient cytoplasm. The effects of non-preactivation and electrical preactivation of recipient cytoplasm, prior to fusing a donor nucleus, on the profile of nuclear remodelling in the nuclear transplant rabbit embryos were evaluated. The embryos of 16-cell stage were collected and synchronized to G1 phase of 32-cell stage. The recipient cytoplasms were obtained by removing the first polar body and chromosome mass by non-disruptive microsurgical procedure. The separated G1 phase blastomeres of 32-cell stage were injected into non-preactivated recipient cytoplasms. Otherwise, the enucleated recipient cytoplasms were preactivated by electrical stimulation and the separated G1 phase blastomeres of 32-cell stage were injected. After culture until 20h post-hCG injection, the nuclear transplant oocytes were electrofused by electrical stimulation. The nuclei of nuclear transplant embryos fused into non-preactivated and/or preactivated recipient cytoplasm were stained by Hoechst 33342 at 0, 1.5, 2, 4, 6, 8, 10 hrs post-fusion and were observed under an fluorescence microscopy. Accurate measurements of nuclear diameter were revealed with an ocular micrometer at 200$\times$. Upon blastomere fusion into non-preactivated recipient cytoplasm, a prematurely chromosome condensation at 1.5 hrs post-fusion and nuclear swelling at 8 hrs post-fusion were occurred as 91.6% and 86.1%, respectively. But the nuclei of nuclear transplant embryos fused into preactivated recipient cytoplasm, as o, pp.sed to non-preactivated recipient cytoplasm, were not occurred chromosome condensation and extensive nuclear swelling. Nuclear diameter fused into non-preactivated and preactivated recipient cytoplasm at hrs post-fusion was 30.2$\pm$0.74 and 15.2$\pm$1.32${\mu}{\textrm}{m}$, respectively. These results indicated that onset of unclear condensation and swelling which was associated with oocytes activation were critical steps in the process of chromatin swelling. Futhermore, complete reprogramming seemed only possible after remodelling of the donor nucleus by chromosome condensation and nuclear swelling.

• ALGAE
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• v.19 no.3
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• pp.201-205
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• 2004

An ectoparasitic din flagellate infesting plank tonic chaetognath, Sagitta crassa Tokioka was found, for the first time, from Korean coasts. In order to identify the species, we investigated detailed morphology of the din flagellate using Nomarski interference optics as well as epifluorescent microscopes. The parasitic din flagellate consists of an oval to rod-shaped cell with a peduncle, by which the organism attaches to the host. The cell is covered with polygonal thecal plates. The nucleus displays two different shapes according to cell cycle stages: in young trophont the nucleus is elongated and shows typical din flagellate nucleus (dinokaryon), while in matured trophont, the nucleus is dome-shaped and non-dinokaryotic. The peduncle is variable in length and is ornamented with the longitudinal striations. All these characteristics point to identity that the ectoparasitic din flagellate infecting Sagitta crassa in Korean coasts is Oodinium inlandicum Horiguchi et Ohtsuka, originally described from the Seto Inland Sea of Japan. Relationship between prevalence and host sizes differed from those in Japan.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.18-18
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• 2001

Despite of importance of integrated events of nucleus and microtubule remodeling in nuclear transferred embryos with somatic cells, little information is available on this subject. In this study we configured chromatin and microtubule organization following somatic cell nuclear transfer in pre- and non-activated bovine oocytes in order to clearify nuclear remodeling process and to demonstrate centrosome inheritance during nuclear transfer. The cumulus-oocyte complexes were collected from slaughterhouse and were matured in vitro for 20 h in TCM 199 supplemented hormone. Matured bovine oocytes were enucleated by aspirating the frist polar body and metaphase chromatin using a beveled pipette. Bovine fibroblast cells were fused into enucleated oocyte by electrical stimulation. Reconstructed oocytes were activated with ionomycine and 6-dimethylaminopurin, and then cultured in CRlaa medium. The organization of nuclear and microtubules were observed using laser-scanning confocal microscopy. At 1 hour after fusion, microtubule aster was seen near the transferred nucleus in most oocytes regardless activation condition. While most of fibroblast nuclei remodeled to premature chromosome condensation (PCC) and to the two masses of chromosome in non-activated oocytes, a few number of fibloblasts went to PCC and multiple pronuclear like structures in activated oocytes. Microtubular spindle was seen around condensed chromosome. Gamma-tubulin was detected in the vicinity of condensed chromosome, suggesting this is a transient spindle. The spindle seperated nucleus into two masses of chromatin which developed to the pronuclear like structures. Two pronuclear like structures were than apposed by microtubular aster and formed one syngamy like nuclear structure at 15 h following nuclear transfer. At 17 to 18 h after fusion, two centrosomes were seen near the nucleus, which nucleates micrtubules for two cell cleavage. While 31% of reconstructed oocytes in non-activated condition developed to morulae and blastocysts, a few reconstructed oocytes in pre-activated condition developed to the blastocyst. These results suggested introduction of foreign centrosome during nuclear transfer, which appeared to give an important role for somatic cell nuclear reprogramming.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.2
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• pp.57-61
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• 2008

Non-nucleus Abalone half pearls were cultured by a new technique and their structural characteristics were analyzed using an electron microscopy. This technique was found to grow the pearls depending on the shape of the internal organ of an abalone because this technique induces the pearl layers without adding any nucleus on the specified damage region of a shell. The obtained pearls exhibit natural shapes with a specific luster. The SEM analysis shows that the pearl layers are about $0.34{\mu}m$ with an uniform thickness and the surface of the shell is characterized by the pyramid-shaped bulge with a regular arrangement, which is a typical feature of single-shell. These characteristics of the pearls are thought to develop in the highly-valued Korean gems.

• The Korean Journal of Zoology
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• v.34 no.1
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• pp.44-53
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• 1991

Distribution of the antigens during the cell cycle of amoebae was followed by immunof-luorescence microscopy using a monoclonal antibody against the nucleus as a probe. While the cells were in the interphase, the antigen was localized on the nucleus membrane. But it was dispersed all over the cytoplasm during mitosis and cytokinesis. The molecular weights of the immunoreacted antigens were 210 KD and 190 KD as determined by SDS PAGE and western blotting of the purified nuclei. The antigens were not soluble in non-ionic detergent, but were released from the nucleus by incubation with 0.05 M sodium carbonate, pH 10.6 or with 8 M urea at serial chemical extraction. Thus the antigens appeared to be peripheral proteins of the nurBeus envelope. The isoelectic point of both antigens was 7.64 as determined by 2 D PAGE and transfer blotting. Considering the peiipherd association with the nucleus membrane and the dispersed distribution during mitosis, the antigens could be lamin like proteins. Hourever, it appears also possible that they are the component molecules of the unusually structured aurous lamina of amoeba nucleus since they have the large molecular weight and the basic pl.

• MALSORI
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• no.19_20
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• pp.58-87
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• 1990

According to Government Phonology, at 1 phonological positions save the domain's head must be licensed in order to appear in the syllable structure. A non-nuclear head is licensed by the following nucleus, and the nuclei with phonetic content are licensed through government by the nuclear head of the domain at the level of the nuclear projection. Therefore, in the theory of Government Phonology it is claimed that words always end with a nucleus. With regard to the licensing of empty nuclei, Kaye(1990a) proposes the 'Empty Category Principle' and its sub-theory of 'Projection Government'. Government Phonology claims that a nucleus which dominates a vowel that regularly undergoes elision in certain contexts is underlyingly empty. This underlying empty nucleus is not manifested phonetically when it is properly governed by an unlicensed(i, e, a nucleus filled with a full vowel). It is when proper government fails to apply, that the empty nucleus is phonetically Interpreted. The purpose of this paper is to present a principled account of the process of $[i]{\Leftrightarrow}{\emptyset}$ alternation in Korean. Following Kaye's proposal, we assume that [i] of Korean is underlyingly empty. This position is pronounced as [i] if it is unlicensed, and is not phonetically realized if is licensed. Empty nuclei ape devided into two categories: domain-internal and domain-final. Firstly, we consider the question why Korean has little word ending with [i]. As for this, ECP states that domain-final empty nuclei are not pronounced if the language licenses domain-final empty nuclei. Whether a final empty nucleus may occur in the structure is parametric variation. This property is seen from the fact that words may appear to end in consonants in this language. Since Korean abounds with words ending in a consonant, it licenses domain-final empty nuclei. Therefore, it is quite natural that Korean has little word ending with [i]. Secondly, word-internal empty nuclei of Korean respect proper government and inter-onset government. That is, an empty nucleus in word-internal position will be pronounced with the vowel [i] if either proper government or inter-onset government fail to apply. Inter-onset government refers to the government established between two onsets across an empty nucleus. Thirdly, we consider words ending with [i], which seems to be exceptional to the final licensing. Host of them are. either mono-syllabic verbs(for instance, [s'i-] 'to write') or derived adjectives ending with [p'i] (for instance, [kip'i-] 'be happy'). As for the former, the 'inaccessibility for proper government' is applied because the empty nucleus appears in the first syllable. In latter case, domain-final empty nuclei are pronounced as [i] because of government-licensing. That is, final empty nucleus is pronounced to license the preceding onset dominating negatively charmed segments which empty nucleus of Korean cannot license.

• Korean Journal of Animal Reproduction
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• v.23 no.1
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• pp.37-43
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• 1999

The image analyser was used for the measurement of the morphological changes of the spermatogenic cells and seminiferous tubules in the pheasant during the breeding and non breeding season. 1. The seminiferous tubules were enlarged 2.57 times during the breeding season than during the non breeding season. Only Sertoli cells and spermatogonia in the seminiferous tubules can be found during the non breeding season. 2. There is no significantly difference in the ratio of nucleus area against that of cell size in the spermatogonium between breeding and non breeding season. The ratio of area was 28.71% and 29.11%, respectively. However, the enlargement of spermatogonium was noticed during the non breeding season. 3. The highest value of the ratio of the nucleus area against that of cell size among the germ cells was measured 37.40% in the pachytene phase of the spermatocyte during the breeding season. 4. The ratio of nucleus area against that of cell size in the spermatid was 22.53%.

• Journal of Acupuncture Research
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• v.19 no.1
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• pp.159-174
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• 2002

Objective : The meridian theory in oriental medicine explains that each acu-point has a characteristic functional effect. It will be supposed that an acupuncture stimulation on different acu-point evokes different activation on different areas in the central nervous system(CNS) according to the meridian theory. On this supposition, our group tried the semi-quantitative [14C]2-deoxyglucose([14C]2-DG) autoradiography on the acupuncture stimulation to the hindlimb acu-points of Sprague-Dawley rats. Methods : A venous catheter for the intravenous administration of isotope was equipped in the right external jugular vein on 3 days prior to the [14C]2-DG study. On the day of the study, two acupuncture needles were inserted into the ST36(Zusanli) or LR3(Taichong) on the left hindlimb. Electro-acupuncture stimulation (2 Hz, 5 ms, 1~3 mA, 15 minutes) started just before the i.v. injection of [14C]2-DG ($25{\mu}Ci/rat$). The brain and the spinal cord were removed and processed for the [14C] 2-DG autoradiography. Results : The EA stimulation on ST36 reveals over 120% metaboilc activation in Arcuate nucleus, Anterior pretectal nucleus, Dorsal cochlear nucleus, Interposed cerebellar nucleus, and Nucleus of Darkschewitsch. The EA stimulation on LR3 reveals over 120% metaboilc activation in Lateral habenula nucleus, Medial vestibular nucleus, Ventromedial thalamic nucleus, Anteroventral thalamic nucleus, Anterior cingulate cortex, Dentate gyrus, Antero cortical amygdaloid nucleus, Anterior pretectal nucleus, and Dorsal tegmental nucleus compared with the non EA stimulation control group. Conclusion : These results demonstrate that the different acu-points evoke the different activations in brain areas. And with this functional brain mapping study, a new scientific elucidation for the basis of the acupuncture-meridian theory in oriental medicine through differences of activated area in CNS according to the each acupuncture point.

• ALGAE
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• v.19 no.2
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• pp.79-90
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• 2004

Nuclear DNA contents of spermatia from eight ceramiacean and four dasyacean algae (Ceramiales, Rhodophyta) and microspores from two land plants were estimated by fluorescence microscopic image processing and their nuclear SSU rDNA sequence data were analyzed. In frequency distribution patterns, the DAPI-stained nuclear volume (NV) of spermatia showed two peaks corresponding to 1C and 2C. Nuclear 2C DNA contents estimated from NV were 0.45-2.31 pg in ceramiacean and 0.40-0.57 pg in dasyacean algae and 8.42-9.51 pg in two land plants, Capsicum annuum and Nicotiana tabacum. By nuclear patterning of vegetative cells derived from an apical cell, 2C DNA contents of spermatia were 2.31 pg in an alga having uninucleate and non-polyploid nucleus (Aglaothamnion callophyllidicola), 0.45-1.94 pg in algae having uninucleate and polyploid nucleus (Antithamnion spp. and Pterothamnion yezoense), and 0.40-0.62 pg in algae having multinucleate and non-polyploid nuclei (Griffithsia japonica and dasyacean algae). Each mature spermatium and microspore (pollen grain) seemed to have a 2C nucleus, which may provide a genetic buffering system to protect the genetic content of a spermatium and microspore from potentially lethal mutations. Nuclear DNA content and SSU rDNA sequence of Antithamnion sparsum from Korea were reasonably different from those of Antithamnion densum from France. The data did not support the previous taxonomic studies that these two taxa could be conspecific.

• Phonetics and Speech Sciences
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• v.6 no.4
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• pp.109-115
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• 2014

Fricated nuclei in Nuosu Yi were found to be more correctly described as fricated vowels, rather than syllabic fricatives due to the presence of clear formant structures typical of front vowels. In this exploratory study, two types of fricated nuclei were examined: retroflex "yr" and non-retroflex "y". The retroflex nucleus "yr" had higher F1 and lower F3 than non-retroflex "y", indicating a lower tongue height. On the other hand, F2 was found to correlate not with nucleus retroflexion, but instead with onset consonant retroflexion: F2 was higher following retroflex onsets, in both vowels. This effect was persistent through the entire vowel, suggesting a phonological effect, rather than a coarticulatory one. Interpretation of the F2 results require accompanying articulatory data since the usual coupling of F2 and tongue backness does not always hold for retroflex vowels. Examining the articulation of the fricated nuclei in Nuosu Yi is a direction for future research.