The domains of laryngeal feature lenition effects in Chonnam Korean

This paper investigates the domain of two aspects of laryngeal features (voicing and voicing onset time) in the Chonnam dialect of Korean. In Korean, voiceless lenis stops, /p, t, k/, sometimes become voiced between voiced segments. Traditionally, this voicing has been discussed as occurring "within a word". Recently, Cho (1989) suggested that lenis stop voicing happens within a phonological phrase. To test this, utterances of various constructions (mostly from Cho 1989) were produced by three Chonnam speakers at three different tempi (slow, normal, fast) with three repetitions. An electroglottograph (EGG) was recorded simultaneously with an audio wave. The results show that word initial lenis stops were almost always voiced within the "accentual phrase" but not within the Phonological Phrase. A second experiment was run for the other laryngeal feature, VOT, to see whether the domain is an accentual phrase as in the case of lenis stop voicing or something else. One, two, or three-syllable words, where a test syllable [pha] was either at a word initial or medial position and phrase initial or medial position, were put in the frame sentence. Sixty four sentences were read with two different accentual phrasings. The result shows that VOT durations of [ph] are significantly different between word initial and medial as well as accentual phrase initial and medial. This suggests that there is a hierarchy of prosodic level in Chonnom Korean: a prosodic word and an accentual phrase

Interference for 'new' versus 'similar' vowels in Korean speakers of English

This paper tests Flege's (1987) Speech Learning Model and Bohn and Flege's (in press) hypothesis about the 'deflected' realization rule of a 'similar' L2 vowel. It is shown that Korean-English bilinguals' production of new English vowels, /I, U/, conforms to Flege's prediction. However, their production of similar English vowels, /i, u, U/, conformed to neither Flege's model nor to Bohn and Flege's hypothesis. We especially examined the interference between Korean and English high vowels, /i, I, U, u/, and /U/ based on 8 Korean-English bilinguals with different years of residence in the States, 4 English monolinguals and 3 Korean monolinguals. Formant values of English vowels produced by Korean-English bilinguals with different years of residence in America were compared with those of English monolinguals. For the vowel /i/, Flege's notion of 'similar' L2 vowels needs be redefined to distinguish similar and identical vowels. He may need either some continuous measures or more systematic criteria to categorize whether a phone in L2 is new or similar to phones in L1

Prosodic Structure and Focus Prosody of South Kyungsang Korean

This paper shows how focus prosody of South Kyungsang Korean interacts with the prosodic structure of the dialect. Based on the prosodic structure defined by intonation, it is claimed that the domain of lexical pitch accent assignment is a Prosodic Word, but the prosodic domain of focus, or the realization of focus prominence, is an Accentual Phrase. This model can explain the phenomenon of mismatch between the domain of semantic focus and the domain of accent/prosodic prominence

Listeners integrate pitch and durational cues to prosodic structure in word categorization

In this study we investigate how listeners perceive vowel duration as a cue to voicing based on changes in pitch height, using a 2AFC task in which they categorized a target word from a vowel duration continuum as coat or code. We consider this issue in light of (1) psychoacoustic perceptual interactions between pitch and duration and (2) compensatory effects for prosodically driven patterning of pitch and duration in the accentual/prominence-marking system of English. In two experiments we found that listeners' interpretation of pitch as a psychoacoustic, or prosodic event is dependent on continuum step size and range. In Experiment 1 listeners exemplified the expected psychoacoustic pattern in categorization. In Experiment 2, we altered the duration continuum in an attempt to highlight pitch as a language-specific prosodic property and found that listeners do indeed compensate for prosodically driven patterning of pitch and duration. The results thus highlight flexibility in listeners' interpretation of these acoustic dimensions. We argue that, in the right circumstances, prosodic patterns influence listeners' interpretation of pitch and expectations about vowel duration in the perception of isolated words. Results are discussed in terms of more general implications for listeners' perception of prosodic and segmental cues, and possibilities for cross-linguistic extension

Exposure to air pollution during preconceptional and prenatal periods and risk of hypertensive disorders of pregnancy: a retrospective cohort study in Seoul, Korea

Background Previous studies suggested associations between prenatal exposure to air pollution and hypertensive disorders of pregnancy. We explored the associations between ambient concentrations of five major air pollutants during preconceptional and prenatal periods and three hypertensive disorders of pregnancy in Seoul, Korea, using a population-representative cohort. Methods We obtained heath and demographic data of pregnant women residing in Seoul for 2002–2013 from the Korean National Health Insurance Service–National Sample Cohort. For mothers individual exposures to air pollution, we computed concentrations of particulate matter ≤10 μm in diameter (PM10), nitrogen dioxide (NO2), carbon monoxide (CO), sulfur dioxide (SO2), and ozone (O3) during 1, 3, 6, and 12 months to birth using regulatory monitoring data in Seoul. The associations between air pollution and hypertensive disorders were explored by using logistic regression models after adjusting for individual confounders. Results Among 18,835 pregnant women in Seoul, 0.6, 0.5, and 0.4% of women developed gestational hypertension, preeclampsia, and preeclampsia requiring magnesium sulfate (Mg-preeclampsia), respectively. Although most odds ratios (ORs) were not statistically significant, we found increasing risk gradients with disease severity depending on the pollutant. There was the association between PM10 during 6 months to birth and gestational hypertension (OR for an interquartile range increase = 1.68 [95% confidence interval = 1.09–2.58]). NO2 and ozone during 12 and 1 month, respectively, before birth were associated with Mg-preeclampsia (1.43 [1.01–2.03], 1.53 [1.03–2.27]). Conclusions We observed positive associations of exposure to some air pollutants before and during pregnancy with hypertensive disorders of pregnancy among the Korean general population. Future studies with refined exposure metrics should confirm our findings.This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2013R1A6A3A04059017, 2016R1D1A1B03933410 and 2018R1A2B6004608) and the National Cancer Center of Korea (NCC-1810220-01). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscrip

The Effect of Ca-P Coated Bovine Bone Mineral on Bone Regeneration around Dental Implant in Dogs

There are many obstacles to overcome in implant dentistry. The bony defect around implant can be seen in immediate installation procedures. Following tooth extraction, however, a socket often presents dimensions that may be considerably greater than the dimensions of a conventional implant

Enhanced cytotoxic effect of radiation and temozolomide in malignant glioma cells: targeting PI3K-AKT-mTOR signaling, HSP90 and histone deacetylases

BACKGROUND: Despite aggressive treatment with radiation therapy and concurrent adjuvant temozolomide (TMZ), glioblastoma multiform (GBM) still has a dismal prognosis. We aimed to identify strategies to improve the therapeutic outcome of combined radiotherapy and TMZ in GBM by targeting pro-survival signaling from the epidermal growth factor receptor (EGFR). METHODS: Glioma cell lines U251, T98G were used. Colony formation, DNA damage repair, mode of cell death, invasion, migration and vasculogenic mimicry as well as protein expression were determined. RESULTS: U251 cells showing a low level of methyl guanine transferase (MGMT) were highly responsive to the radiosensitizing effect of TMZ compared to T98G cells having a high level of MGMT. Treatment with a dual inhibitor of Class I PI3K/mTOR, PI103; a HSP90 inhibitor, 17-DMAG; or a HDAC inhibitor, LBH589, further increased the cytotoxic effect of radiation therapy plus TMZ in U251 cells than in T98G cells. However, treatment with a mTOR inhibitor, rapamycin, did not discernibly potentiate the radiosensitizing effect of TMZ in either cell line. The mechanism of enhanced radiosensitizing effects of TMZ was multifactorial, involving impaired DNA damage repair, induction of autophagy or apoptosis, and reversion of EMT (epithelial-mesenchymal transition). CONCLUSIONS: Our results suggest possible strategies for counteracting the pro-survival signaling from EGFR to improve the therapeutic outcome of combined radiotherapy and TMZ for high-grade gliomas

Effect of the glyceryl monooleate-based lyotropic phases on skin permeation using in vitro diffusion and skin imaging

AbstractGlyceryl monooleate (GMO) is a polar lipid that can exist in various liquid crystalline phases in the presence of different amounts of water. It is regarded as a permeation enhancer due to its amphiphilic property. Various phases of GMO/solvent system containing sodium fluorescein were prepared to compare permeability using confocal laser scanning microscopy (CLSM). GMO was melted in a vial in a water bath heated to 45 °C. Propylene glycol and hexanediol were homogeneously dissolved in the melted GMO. Sodium fluorescein in aqueous solution was diluted to various ratios and thoroughly mixed by an ultrasonic homogenizer. Each GMO/Solvent system with fluorescein was applied onto the epidermal side of excised pig skin and incubated overnight. CLSM was performed to observe how the GMO/solvent system in its different phases affect skin permeability. Cubic and lamellar phase formulations enhanced the fluorescein permeation through the stratum corneum. A solution system had the weakest permeability compared to the other two phases. Due to the amphiphilic nature of GMO, cubic and lamellar phases might reduce the barrier function of stratum corneum which was observed by CLSM as fluorescein accumulated in the dermis. Based on the results, the glyceryl monooleate lyotropic mixtures could be applied to enhance skin permeation in various topical and transdermal formulations