Towards an optimal account of diachronic chain shifts

Sang-Cheol Ahn 한국음운론학회 2004 음성·음운·형태론 연구 Vol.10 No.1

Ahn, Sang-Cheol. 2004. Towards an optimal account of diachronic chain shifts. Studies in Phonetics, Phonology and Morphology 10.1. 43.67. This paper reanalyzes the historical change, Grimm’s law from a new per-spective, employing Dispersion Theory (Flemming 1995, 1996). To this end, I will first show that Grimm’s law can better be explained in terms of “push chain” and the cause of the chain shift might be the heavy markedness of the voiced aspirated stops. Due to the markedness, they changed to voiced stops, not fricatives (Iverson & Salmons 1999, 2001), resulting in a push chain: i.e., [+voice, +aspirated] > [-aspirated], [+voice] > [-voice], [-voice] > [+continuant]. Second, in addition to the consideration on markedness and ease of articulation, I argue for further consideration for chain shifts, pattern evaluation, since the changes of the single segments cannot be considered separately; they are evidently parts of one great linguistic movement, obey-ing the “no merge” principle. Third, in the explanation of each step of the changes, I will argue that local conjunction of constraints may take a crucial role in the selection of optimal outputs and eliminates the necessity of con-straint re-ranking. Therefore, regardless of the historical stage, we can maintain the same constraint ranking. Moreover, as the conjoined constraint indicates the apparent trigger of the whole shift, we can avoid the so-called “chicken and egg” problem (McMahon 2000b). Furthermore, we may not face the philosophical problem of Optimality Theory (Kager 1999) since the individual constraints *Asp and *Voice take their roles in the various stages, while the conjoined constraint filters out the worst candidates. (Kyung Hee University)

Antibiosis and Bacteriocin Production of Lactic Acid Bacteria Isolated from Kimchi

Sung-Sook Bae,Cheol Ahn 한국식품영양과학회 1997 Preventive Nutrition and Food Science Vol.2 No.2

In other to elucidate roles of lactic acid bacteria(LAB) for the antibiosis occurring in the fermenting environment of Kimchi, 2,052 strains of LAB were isolated from Kimchi. Fifty two strains which showed antagonistic effect against 4 indicator strains were finally selected and investigated. Based upon responses to protease treatment, antibiosis of the 52 strains of LAB were classified into 3 types. Type A antibiosis resulted from action of antibiotic-like substances which were not affected by protease treatment and which had broad action spectra against even natural inhabitants of Kimchi. Type B antibiosis was due to bacteriocinlike substances which were very sensitive to treatment of protease and more effective against foreign bacteria than original inhabitant microflora. Type C antibiosis was owing to proteinaceous compounds which were activated or induced by the presence of protease and then exerted antibacterial activities. Therefore, lactic acid bacteria appeared to contribute to antibiosis of Kimchi by the concerted action of these three different types of antibacterial compounds. As one of model system for type B bacteriocin, the antagonistic compound produced by LAB31-9 as well as the producer strain itself was further characterized. Strain LAB31-9 was identified as L. casei. Bacteriocin produced by LAB31-9 was proteinaceous and stable over wide range of pH and to various solvents, but very labile to heat treatment. Its mode of action was bactericidal. Based upon these data, bacteriocin produced by LAB31-9 was named as 'caseicin K319'. Genetic determinant for the bacteriocin production of LAB31-9 was located in the chromosome.

A case of angular pregnancy: Is the expectant management possible?

( Sung Hye Jeon ),( Ho Yeon Kim ),( Geum-joon Cho ),( Soon-cheol Hong ),( Min-jeong Oh ),( Hai-joong Kim ),( Ki Hoon Ahn ) 대한산부인과학회 2018 대한산부인과학회 학술대회 Vol.104 No.-

Angular pregnancy is defined as implantation of the embryo just medial to the uterotubal junction, in the lateral angle of the uterine cavity and medial to the round ligament. It should be distinguished from interstitial pregnancy because the management of the patient varies according to the diagnosis and it can be emergency conditions. A 29-year-old, parity 0-0-0-0 woman visited our hospital for a routine antenatal examination at 5 weeks and 5 days of gestation. She denied any abnormal medical and surgical histories. Transvaginal sonography showed a gestational sac without fetal heart beat located in the left lateral angle in the uterine cavity. It was difficult to differentiate the cornual pregnancy from interstitial ectopic pregnancy. Initial hCG level at the first visit was 10001.1 mIU/mL. For detailed information, MRI images were obtained at 6 weeks and 4 days of gestation. The radiologic finding was more suspicious of angular pregnancy and the radiologist recommended further observation if clinically indicated. At 7 weeks and 6 days of gestation, fetal heartbeat was confirmed by transvaginal sonography. The pregnant woman had mild lower abdominal cramps and intermittent vaginal spotting which might be a sign of complication that needs surgical treatment. Otherwise, antenatal tests were normal. At the present time of this report, the gestational age is 24 weeks and 1 days and the fetal viability is expected. She does not have any abnormal symptoms and signs. Sonography shows normal uterus shape without protrusion of uterine angle, and fetal development is also within normal range. The thickness of the myometrium is maintained above 3 mm. We report a rare case of angular pregnancy that is being successfully maintained with a literature review. Our case shows that in case of cornual pregnancy suspicious of angular pregnancy, an expectant management with close observation needs to be considered as a treatment option.

HARMONY PROCESSES IN KOREAN

Ahn, Sang-Cheol 경희대학교 언어연구소 1985 언어연구 Vol.6 No.-

Stemness Evaluation of Mesenchymal Stem Cells from Placentas According to Developmental Stage: Comparison to Those from Adult Bone Marrow

Sung, Hwa Jung,Hong, Soon Cheol,Yoo, Ji Hyun,Oh, Jee Hyun,Shin, Hye Jin,Choi, In Young,Ahn, Ki Hoon,Kim, Sun Haeng,Park, Yong,Kim, Byung Soo The Korean Academy of Medical Sciences 2010 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.25 No.10

<P>This study was done to evaluate the stemness of human mesenchymal stem cells (hMSCs) derived from placenta according to the development stage and to compare the results to those from adult bone marrow (BM). Based on the source of hMSCs, three groups were defined: group I included term placentas, group II included first-trimester placentas, and group III included adult BM samples. The stemness was evaluated by the proliferation capacity, immunophenotypic expression, mesoderm differentiation, expression of pluripotency markers including telomerase activity. The cumulative population doubling, indicating the proliferation capacity, was significantly higher in group II (<I>P</I><0.001, 31.7±5.8 vs. 15.7±6.2 with group I, 9.2±4.9 with group III). The pattern of immunophenotypic expression and mesoderm differentiation into adipocytes and osteocytes were similar in all three groups. The expression of pluripotency markers including ALP, SSEA-4, TRA-1-60, TRA-1-81, Oct-4, and telomerase were strongly positive in group II, but very faint positive in the other groups. In conclusions, hMSCs from placentas have different characteristics according to their developmental stage and express mesenchymal stemness potentials similar to those from adult human BMs.</P>

Pleomorphic Adenoma with Sarcomatous Change in a Lacrimal Gland

Sung, Kyoung-Su,Kim, Dae-Cheol,Ahn, Hee-Bae,Song, Young-Jin The Korean Neurosurgical Society 2015 Journal of Korean neurosurgical society Vol.57 No.6

A 69-year-old man was referred with left exophthalmos. Computed tomographic (CT) findings detected a well-circumscribed mass in the left side of the intraorbital cavity. At that time, he refused the further evaluation and treatment. About three years later, the size of the mass had enlarged, and the patient's symptoms were getting worse. The mass was completely removed with frontotemporal craniotomy and superolateral orbitotomy. In operative findings, the mass had originated in the lacrimal gland and was well-encapsulated without invasion to the surrounding tissue. In the pathologic findings, the tumor consisted of pleomorphic adenoma with osteosarcomatous change of stromal components. Postoperatively, the adjuvant radiotherapy was done four weeks later. The patient's symptoms were improved. The pleomorphic adenoma with osteosarcomatous change is extremely rare and appropriate treatment is not clearly established. We would like to report this rare case with a review of the literature.

Constraints in Verbal Compounding

Sang-Cheol Ahn 국제한국언어학회 1998 korean Linguistics Vol.9 No.-

English Interdental Substitution

( Sang Cheol Ahn ) 한국영어영문학회 2003 영어 영문학 Vol.49 No.5

The purpose of this paper is to describe the various types of English interdental substitution within the framework of Optimality Theory. For this Purpose, I will first categorize the substitution patterns into four major types and discuss the phonological implication of each pattern. During the discussion, I will propose that Ident-manner be exploded for [cont] and other manner features such as [stiff vocal folds] and [sibilant]. As for the positional variation occuring in Dutch and Korean, I will argue for positional markedness, rather than positional faithfulness. During the discussion on Korean, I will also discuss alternative accounts and point out their problems such as the lact of uniformity in explanation. for instance, most earlier studies, focussing on the substitution of the voiceless interdental, cannot deal with the substitution of the voiced one. Finally, I will show how this current analysis can be used for the substitution of other English fricatives.

Isolation and Structural Determination of Squalene Synthase Inhibitor from Prunus mume Fruit

( Sung Won Choi ),( Nam Yoon Hur ),( Soon Cheol Ahn ),( Dong Seob Kim ),( Jae Kwon Lee ),( Dae Ok Kim ),( Seung Kook Park ),( Byung Yong Kim ),( Moo Yeol Baik ) 한국미생물생명공학회 2007 Journal of microbiology and biotechnology Vol.17 No.12

Schawa Insertion In English

( Sang Cheol Ahn ) 한국영어영문학회 2008 영어 영문학 Vol.54 No.6