• Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.25-31
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• 1999

Developmental morphology of the red alga, Osmundea crispa (Hollenberg) Nam from California was studied on the basis of liquid-preserved and herbarium specimens. Vegetative axial segment of the species produces two pericentral cells and one trichoblast. Spermatangial filaments (branches) are derived from apical and epidermal cells in pocket-shaped apical pit with an ostiole-like upper opening. Procarp-bearing segment of female trichoblast produces five pericentral cells, of which the fifth functions as supporting cell of carpogonial branch. Tetrasporangial production occurs in random epidermal cells in apical pit of branchlets, and two presporangial cover cells show parallel arrangement to stichidial axis. As this vegetative and reproductive development is included in the generic delineation of Osmundea Stackhouse, O. crispa among the known Osmundea species is characterized by habit forming compact cushion-like clump with angular to terete thallus. It is also distinguished from O. hybrida (AP. de Candolle) Nam without the compressed thallus by the number of pericentral cells in procarp-bearing segment and shape of spermatangial pit. Taxonomic implication of the shape of spermatangial pit is also included.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.2
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• pp.160-168
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• 2017

Optimizing the conditions for stem cell culture is an essential prerequisite for the efficient utilization of stem cells. In the culture of fish embryonic stem cells (ESCs) or ESC-like cells, embryo extracts are important for stable growth, but there is no rule for determining the developmental stage of the embryos used to obtain extracts. Therefore, this study investigated the effects of the developmental stage of extract donor embryos on the culture of Oryzias dancena ESC-like cells. O. dancena ESC-like cells were cultured in different media containing each of four types of embryo extract depending on the developmental stage of the extract donor embryos. Growth, morphology, colony-forming ability, alkaline phosphatase (AP) activity, and embryoid body (EB) formation of the cells were investigated. While the developmental stage of the extract donor embryos did not influence the growth, morphology, AP activity, or EB formation of ESC-like cells, colony-forming ability was affected and the pattern of the effects differed completely between the two ESC-like cells investigated. These results suggest that the developmental stage of extract donor embryos should be selected carefully for the culture of ESC-like cells, according to the research purpose and type of cell line.

• Korean Journal of Veterinary Research
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• v.33 no.1
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• pp.171-178
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• 1993

The present study was carried out to investigate the developmental potency to blastocyst after freezing and thawing of nuclear transplanted 2-cell embryos. The nuclei from 2-, 4- and 8-cell mouse embryos were transferred into enucleated 2-cell embryos, and the reconstituted embryos were submitted to direct current(DC) pulse at output voltage of 2.0 kV/cm for $100{\mu}$ sec to induce cell fusion. The recovery rate and developmental potency to blastocyst after freezing and thawing of nuclear transplanted 2-cell embryos was investigated. 1. The recovery rate of nuclear transplanted 2-cell embryos in normal morphology after freezing and thawing was significantly higher in rapid freezing(DMSO 4.5M) than in slow cooling(p<0.01). 2. When the recovered embryos in normal morphology were cultured in vitro, there were no significant differences in the developmental potency to blastocyst between the freezing methods and the concentrations of cryoprotectant. In summary, these experiments have proved that rapid freezing method(DMSO 4.5M) is effective in nuclear transplanted 2-cell mouse embryos. If improved micromanipulation techniques and freezing are combined, nuclear transplantation technique will contribute to the improvement of productivity in livestock animals.

• Cross-Cultural Studies
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• v.43
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• pp.459-483
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• 2016

The main objective of this paper is to test the major prediction of the Aspect Hypothesis on interlanguage narratives collected from 171 Ibibio ESL learners in a classroom setting using sets of picture stories. Aspect Hypothesis predicts that lexical aspectual classes of verbs would determine the pattern of acquisition and distribution of tense-aspect morphology at the very early stages of L2 acquisition of tense-aspect verbal morphology. That is, telic verbs would be marked with the past tense-aspect verbal morphology before atelic verbs in the interlanguage of ESL learners irrespective of their L1 background. The results of our data analyses show a significant effect from the lexical aspect on the acquisition and distribution of tense-aspect morphology with chi-square statistics of ($x^2=196.92$,df = 6, n = 1664, p = <.0001). However, the effect of the lexical aspect is shown to be more prominent among Ibibio ESL learners at higher levels of proficiency. This is contrary to the prediction regarding Aspect Hypothesis. The paper concludes that the influence of the lexical aspect on the pattern of acquisition and distribution of tense-aspect morphology may be universal but the actual point along the developmental pathway when such influence is obtainable is yet to be determined. This calls for more research into the pattern of the L2 acquisition of tense-aspect verbal morphology.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.510-520
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• 2019

To investigate the morphology characteristics of air layer in the air cavity, a numerical method with the combination of RANS equations and VOF two-phase-flow model is proposed for a plate with air cavity. Based on the model above, the dynamic and developmental process of air layer in the air cavity is studied. Numerical results indicate that the air layer in the plate's air cavity exhibits the dynamic state of morphology and the wavelength of air layer becomes larger with the increasing speed. The morphology of air layer agrees with the Froude similarity law and the formation of the air layer is not affected by the parameters of the cavity, however, the wave pattern of the air layer is influenced by the parameters of the cavity. The stable air layer under the air cavity is important for the resistance reduction for the air layer drag reduction.

• Journal of Integrative Natural Science
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• v.16 no.2
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• pp.69-74
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• 2023

In Dictyostelium , there are 15 Ras subfamilies, including 11 Ras, 3 Rap, 1 Rheb. The Ras proteins are involved in regulating various cell processes as switch proteins. The functions of many Ras proteins have been identified, but some of Ras proteins have not yet been identified. Here, we focused on identifying the roles of RasW among them. To investigate the functions of RasW in cell morphology, cell migration, and development in Dictyostelium , we compared the phenotypes of wild-type cells and rasW null cells. rasW null cells showed a larger, more spread-out morphology and reduced cell motility compared to wild-type cells. There was no significant difference between wild-type cells and rasW null cells during multicellular developmental process. These results suggest that RasW is involved in regulating cell morphology and cell migration in Dictyostelium.

• Journal of Embryo Transfer
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• v.18 no.1
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• pp.27-33
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• 2003

The study was carried out to investigate the effects of morphology, reproductive cycle, incubation time and activation of oocytes in vitro maturation of canine oocytes and development of canine IVM/IVF embryos. The results were summarized as follows: 1. The developmental rates to 16 cells of fresh, salts and 4$^{\circ}C$-stored oocytes with and without cumulus cells were 14.3%, 5.0% and 7.5%, 2.8% and 5.7%, 0.0%, respectively. The rate of oocytes with cumulus cells(5.7%~14.3%) was higher than that of denuded oocytes(0.0%~5.0%). 2. The developmental rate to If cells of in vitro cultured oocytes recovered from ovaries collected at different stages of the reproductive cycle were 0.0%, 10.7%, 1.5%, respectively. 3. The developmental rate to 16 cells of fresh oocytes with cumulus cell cultured for 24, 32 and 48 hrs in $CO_2$ incubator were 0.0%, 5.3%, 11.8%, respectively. The rate of oocytes cultured for 48 hrs was higher than that oocytes cultured for 24 and 32 hrs. 4. The development to If cells treated activation and non-activation oocytes were 15.0%, 6.7%, respectively. The rate of oocytes treated activation was higher than that oocyte treat non-activation.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.108-108
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• 2003

The purpose of this is to investigate the effects of vitrification in open pulled straws (OPS) on in vitro survival of porcine embryos. Blastocysts were produced by in vitro fertilization of slaughterhouse-derived, in vitro matured oocytes with frozen-thawed boar semen, and subsequent culture on granulosa cell monolayer. After frozen-thawing, embryos were culture in NCSU-23 medium with 5 mM hypotaurine, 4 mg/$m\ell$ BSA and 10 ng/$m\ell$ for 48 hrs to survival tests. When blastocysts were frozen-thawed by OPS methods, the embryos with normal morphology were 32.1, 34.5 and 38.9 % in early blastocyst, blastocyst and expanded blastocyat stages. The rates of partial damaged embryos were significantly (P<0.05) higher in early biastocysts than expanded blastocysts. In another experiment, the embryos frozen by OPS methods were cultured for 48 hrs for survival and developmental rates in vitro. The proportions of embryos hatched were 11.8, 20.2 and 33.3% in embryos frozen-thawed at stages of early blastocyst, blastocyst and expanded embryos. On the other hand, The proportions of embryo with normal morphology after culture were 23.5, 25.0 and 33.3% in embryos frozen-thawed at stages of early blastocyst, blastocyst and expanded embryos. These finding indicate the possible broader application for OPS methods that this procedure described is relatively harmless, that it can be used for blastocysts of different developmental stages.

• The korean journal of orthodontics
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• v.46 no.6
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• pp.345-355
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• 2016

Objective: The purpose of this study was to determine whether predicting maturation of the midpalatal suture is possible by classifying its morphology on cone-beam computed tomography (CBCT) images and to investigate relationships with other developmental age indices. Methods: The morphology of the midpalatal suture was assessed by using CBCT images of 99 patients. Axial plane images of the midpalatal suture were classified into five stages according to the classification scheme. To make the assessment more accurate, the morphology and fusion of the midpalatal suture were additionally investigated on coronal cross-sectional planar images and volume-rendered images. Bone age was evaluated using the hand and wrist method (HWM) and cervical vertebrae method (CVM); dental age (Hellman's index), sex, and chronological age were also assessed. To evaluate relationships among variables, Spearman's rho rank test was performed along with crosstabs using contingency coefficients. Results: The HWM and CVM showed strong correlations with the maturation stage of the midpalatal suture, while other indices showed relatively weak correlations (p < 0.01). Through crosstabs, the HWM and CVM showed high association values with CBCT stage; the HWM demonstrated slightly higher values (p < 0.0001). Based on the HWM, the midpalatal suture was not fused until stage 6 in both sexes. Conclusions: Among developmental age indices, the HWM and CVM showed strong correlations and high associations, suggesting that they can be useful in assessing maturation of the midpalatal suture.

• The Journal of the Korean dental association
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• v.50 no.10
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• pp.616-619
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• 2012

The aim of this study was to clarify the arrangement of the zygomaticus major muscle, and to describe morphology of zygomaticus minor muscle. After a detailed dissection, the zygomaticus muscles were observed in 66 embalmed cadavers. It was found that the insertion of zygomaticus major was divided into superficial and deep bands(42/70, 60%). Zygomaticus minor was inserted not only upper lip also alar portion(5/54, 9.2%). The arrangement and insertion patterns of the zygomaticus muscles in this study are expected to provide critical information for understanding or smile pattern and treatment or fold.