The Effects of Wnt Signaling on Neural Crest Lineage Segregation and Specification

Jinsu Song(송진수),Eun-Jung Jin(진은정) 한국생명과학회 2009 생명과학회지 Vol.19 No.10

Neural crest는 신경계의 발생과정에서 생긴 특정화된 외배엽으로서 말초신경계(peripheral nervous system)의 모든 sensory cells과 peripheral cells, unipolar spinal ganglion cell, cranial sensory ganglia, peripheral nerve의 neurolemmal sheath cells, ganglia의 capsule cells, sympathetic ganglia, chromaffin cells, pigment cell 등의 자율신 경계의 대부분의 세포로 분화 한다. 최근pluripotetic neural crest cells의 운명이 이미 제한되어 있으며, 이러한 fate-restricted crest cells이 neural tube에서 emigration된다고 보고된바 있다. 또한 본 연구자는 Wnt와 Wnt의 antagonist가 neural crest cell의 specification이 일어나는 시기에 발현하여, neural crest cell의 segregation과 differentiation에 직접적으로 관여함을 밝혔다. 이를 보다 명확히 규명하기 위해, 본 연구에서는 neural tube에 Wnt-3a expressing cell의 grafting 혹은 dominant negative GSK construct의 electroporation을 통해 Wnt signaling을 modulation 하여 downstream mediator를 조사하였다. Wnt signaling의 stimulation은 neural crest cell의 melanoblast 로의 commitment를 유도하였으며, 이와 더불어 cadherin 7과 slug의 발현을 조절함을 확인하였다. Recent evidence has shown that many pluripotetic neural crest cells are fate-restricted and that different fate-restricted crest cells emigrate from the neural tube at different times. Jin et al. (2001) identified the expression patterns of Wnts and its antagonists at the time that neural crest cells were being specified and suggested that Wnt signaling was involved in the segregation/differentiation of neural crest cells in the trunk in vitro. In this study, we evaluated the effects of Wnt signaling in avian neural crest lineage segregation. To accomplish this, Wnt signaling was disturbed at the time of neural crest segregation and differentiation by grafting Wnt-3a expressing cells and conducting dominant negative glycogen synthase kinase (dnGSK) electroporation. Stimulation of Wnt signaling induced neural crest lineage segregation and melanoblast specification, and increased the expression levels of genes known to be involved in neural crest development such as cadherin 7 and Slug, which suggests that they are involved in Wnt-induced neural crest lineage differentiation into melanoblasts.

근대기 문장(紋章)의 수용 양상과 의미 -국립민속박물관 소장 『가장보(家章譜)』를 중심으로

서정현 한국역사민속학회 2022 역사민속학 Vol.- No.62

A crest is a mark that symbolizes a country, community, or individual. Since the marks representing the state were officially used in the Joseon-Korean Empire during the modern transition period based on the needs for diplomatic and internal symbols, the use of the crest has been gradually expanded to include the insignia of public offices, private school badges, and trademarks. Gajangbo(家章譜) recorded by Jangam Baek Si-yong(藏菴 白時鏞, 1864 ~1939) is a recording showing the use of crests symbolizing the country or the imperial family during the Korean Empire was implemented as a trademark representing the private and corporations at the beginning of the Japanese colonial period. In the process of implementation, Gajangbo also shows the life that the use of the crest has been introduced and enjoyed mainly by the new social leaders. It indicates that similar to the early style of using crests in the country and imperial family, there was an aspect of visualization that symbolized and revealed the family or individual in a specific class. Gajangbo by Baek Si-yong is a record containing about 150 crests that he commissioned and produced between 1916 and 1918. He divided the crests into the family crest, symbolizing the family, and the crest symbolizing individuals and community. Each crest includes the design, meaning, and client. Sometimes, it contains a client's affiliation and the recommender. The information is significant to understand the personal relationship between clients as well as the class who enjoyed the crests. As a result of analyzing the clients of Gajangbo, they were former bureaucrats before and after the Korean Empire. They grew up as high-ranking government officials after the modern period, or newly grew up by running a company based on commerce and industry that had been disregarded during the previous period and having mining rights. As a new social leader class who exerts significant influence at the time, they showed their willingness to lead a new ritual order and take the form of modern people through the enactment and practice of a new exercise of the ‘modern’ style. This research aims to reveal the aspect and meaning of the modern transition period crest through Gajangbo by Baek Si-yong in the National Folk Museum of Korea. Furthermore, this study attempts to investigate the symbolism of the use of crest to the social leaders and what social meaning the trend of crest had. 문장(紋章)은 국가나 단체, 개인 등을 상징하는 표식을 의미한다. 근대 전환기 조선-대한제국에서 외교적․내적 상징물의 필요에 따라 국가를 표상하는 상징물이 공식적으로 사용된 이래 문장의 사용은 외래 문물의 수용과 함께 관공서의 휘장(徽章), 민간의 교표(校標), 상표(商標) 등으로점차 확대되었다고 이해됐다. 장암 백시용(藏菴 白時鏞, 1864~1939)이 기록한 가장보(家章譜)는 대한제국기 국가의 상징으로 등장했던 문장이 단체, 기업을 대표하는 상징(emblem)의 사용으로 이행하는 과정에서 일제강점기 초반 특정 계층을 중심으로 문장이 유입되고 향유되어 온 생활상을 조명할 수 있는 자료이다. 이는 국가 및 황실에서 문장을 활용하던 초기 양식과 유사하게 특정 계층에게서 가문 또는개인을 상징하고 드러내는 시각화의 양상이 나타나고 있었음을 의미한다. 백시용의 가장보는 1916년부터 1918년까지 그가 의뢰를 받아 제작한 문장 150여 개를 담은 기록이다. 그는 문장을 가문의 상징인 ‘가장(家章)’과 개인, 단체의 상징인 ‘문장’으로 구분했다. 이러한 구분에 따라 본문에는 문장의 도안(圖案), 의미, 의뢰인 등이 기재되어 있으며 때때로의뢰인의 소속과 소개인 등이 작성되어 있어 문장을 향유한 계층은 물론, 의뢰인 간 인적 관계를파악할 수 있다. 이를 토대로 가장보의 의뢰인을 분석한 결과 이들은 대한제국 전후 관료 출신으로 근대기 이후 고위관료로 성장한 인물 또는 상공업을 바탕으로 회사를 운영하고, 광업권을 가지는 등 자본을기반으로 근대기에 새롭게 성장한 인물이었다. 이들은 당대에 상당한 영향력을 행사하는 신 사회주도계층으로서 ‘근대적’ 양식의 새로운 예제(禮制)의 제정과 실천을 통해 새로운 예적 질서를 주도하고 근대인의 모습을 갖추려는 의지를 드러낸 것이라 할 수 있다. 이 글은 국립민속박물관 소장 백시용의 가장보를 통해 근대 전환기 문장이 수용된 하나의 양상과 그 의미를 밝히는 것에 목적이 있다. 또 이 시기 신 사회주도계층에게 문장 사용이 어떠한상징성을 가지고 있었고 문장의 유행이 어떠한 사회적 의미를 갖는지 분석하고자 하였다.

Comparison of Femoral Anteversion Angle and Determination of Reliability Measured at Three Different Anatomical References of the Tibial Crest during the Trochanteric Prominence Angle Test

( Ji Hyun Lee ),( Tae Lim Yoon ),( Sil Ah Choi ),( Heon Seock Cynn ) 한국전문물리치료학회 2012 한국전문물리치료학회지 Vol.19 No.4

The trochanteric prominence angle test (TPAT) has been used to measure the femoral anteversion angle between the tibial crest and the vertical line. However, the exact anatomical reference of the tibial crest has not yet been identified in the literature. Thus, the purposes of this research were twofold: first, to compare the femoral anteversion angle measured at three different anatomical references of the tibial crest (the proximal tibial crest, the proximal third of tibial crest, and the proximal half of tibial crest) and, second, to determine inter-and intra-rater reliabilities of the femoral anteversion angle measured at these three different anatomical references of the tibial crest during the TPAT. We recruited 14 healthy subjects, and a total of 28 legs were examined. The TPAT was measured using a digital inclinometer. A 1-way repeated-measure analysis of variance was used to compare the femoral anteversion angle measured at three different anatomical references of the tibial crest, and intraclass correlation coefficients (ICCs) were calculated to determine reliability. The femoral anteversion angle measured at the proximal tibial crest was significantly higher than that at the proximal third of the tibial crest and the proximal half of the tibial crest. The inter-and intra-rater reliabilities of femoral anteversion angle were measured at three anatomic references of the tibial crest were all found to be high during the TPAT (ICC=.90~.98). In conclusion, clinicians should recognize that the different degrees of the femoral anteversion angle could be measured when different anatomical references of the tibial crest were used, and that reliabilities were high when an exact anatomical reference of the tibial crest was used during the TPAT.

Forskolin Effect on the Lineage Specification of Trunk Neural Crest Cells in vitro

Jin, Eun-Jung The Korean Society for Integrative Biology 2002 Korean journal of biological sciences Vol.6 No.1

Recent evidence has suggested that trunk neural crest cell generally assumed to have equivalent differentiation potentials, demonstrate differentiation bias along the anterior/posterior axis. In amphibian and fish, neural crest cells give rise to three chromatophore types, melanophores, xantho-phores, and iridophores. Each pigment cell type has distinct characteristics but there is speculation about the cellular plasticity that exists among them. Neural crest cells migrate along specific routes, ventromedially and dorsolaterally. Neural crest cells that travel dorsolaterally are the first cells to begin migration in the axolotl and are the major contributors to the visible pigment pattern. Many factors and mechanisms that are responsible for guiding migratory neural crest cells along potential pathways or determining their fate remain unknown. A single lineage of the crest, which becomes restricted to one of the three pigment cell types, gives us the opportunity to examine the existence of neural crest stem cell populations and cellular plasticity. Study presented here showed results from recent in vitro studies designed to identify parameters influencing differentiation events of individual neural crest-derived pigment cell lineages. Melanophore production from neural crest explants originating from different levels along the anterior/posterior axis of wild type-axolotl embryos were compared and demonstrate that the differentiation of melanophores is enhanced in subpopulation of neural crest treated with forskolin. Forskolin (an adenylate cyclase activator) increases intracellular CAMP concentration and eventually activates the protein kinase-A signaling pathway. Melanophore number, melanin content, and tyrosinase activity in explants taken from the anterior-most region of the crest increased significantly in response to forskolin treatment. This study suggests implications of region specific influences and developmental regulation in the development of pigment pattern.

치조열 교정을 위한 장골 능선 해면골 재이식술

김석화,김병준,최태현 대한성형외과학회 2011 Archives of Plastic Surgery Vol.38 No.1

Purpose: The anterior iliac crest is a common source for autologous cancellous bone graft. For patients who have previously received cancellous bone grafts from bilateral anterior iliac crests, there may be concerns of whether a sufficient quantity of autologous cancellous bone remains for additional grafts without harvesting it from other sites, such as the posterior iliac crest. Methods: We experienced 3 cases of reharvesting in 2 patients. The diagnosis of the first patient was bilateral facial cleft number3. This patient received bilateral side cleft alveoloplasty with corticocancellous bone graft from the both anterior iliac crest respectively by a previous surgeon. This patient then needed to reharvest the anterior iliac crest cancellous bone to correct an ongoing skeletal problem for the bilateral cleft. The other patient had bilateral incomplete cleft of the primary palate. This patient received left side cleft alveoloplasty with cancellous bone graft from the right anterior iliac crest. Before the patient could receive the alveoloplasty on the other side, a radial head osteotomy and cancellous bone graft was performed by orthopedic surgeons who then used the remaining left iliac crest in order to treat a pulled elbow. For the completion of the right side cleft alveoplasty, the anterior iliac crest cancellous bone needed to be reharvested. Prior to the reharvesting, a preoperative computed tomography scan of the pelvis was obtained to assess the maturity of the donor site regeneration. The grafts were then taken from sites where a greater amount of regeneration was evident. Results: Long term follow ups showed that the grafts were successfully taken. This sufficient volume was obtainable 14 months after the first harvest. Conclusion: Satisfactory results were achieved after the reharvesting of iliac cancellous bone. Thus, it appears that the reharvesting of the iliac bone is a possible alternative to multiple site grafting, use of allograft or bone substitute materials.

CREST-BV: 임베디드 소프트웨어를 위한 Bitwise 연산을 지원하는 Concolic 테스팅 기법

김윤호(Yunho Kim),김문주(Moonzoo Kim),장윤규(Yoonkyu Jang) 한국정보과학회 2013 정보과학회논문지 : 소프트웨어 및 응용 Vol.40 No.2

기존 소프트웨어 테스팅 기법은 개발자가 수동으로 테스트 케이스를 작성해야 하는 비효율성으로 인해 임베디드 소프트웨어의 안정성 확보에 어려움이 있다. Concolic 테스팅 기법은 자동으로 소프트웨어 테스트 케이스를 생성함으로써 기존 소프트웨어 테스팅 기법의 문제를 해결했지만, 임베디드 소프트웨어 테스트에 필수적인 bitwise 연산을 지원하지 않는 문제가 있었다. 본 논문에서는 임베디드 소프트웨어를 위해 bitwise 연산을 지원하는 Concolic 테스팅 개선 방법을 연구하고 오픈 소스 임베디드 소프트웨어 Busybox에 적용하여 기존 연구와 분기 커버리지 및 실행 속도를 비교하였다. Busybox의 10개 유틸리티에 적용한 결과 기존 연구 결과 대비 평균 33%의 분기 커버리지 향상이 있었다. 또한, CREST-BV의 성능 저하 원인을 분석하였다. Conventional testing methods often fail to assure reliability of embedded software due to inefficiency and ineffectiveness of manual test case generation. Concolic testing can address this by automatically generating test cases but has a limitation that does not support bitwise operations critical to embedded software. To address this limitation, we have developed an improved concolic testing technique with bitwise operations support for embedded software. We applied the improved technique to 10 utilities of open-source embedded software Busybox and achieved 33% more branch coverage on average. In addition, we analyzed the performance bottleneck of the improved technique.

목적 지향 콘콜릭 테스팅

정인상(Insang Chung),박정규(Jungkyu Park) 한국정보과학회 2010 정보과학회논문지 : 소프트웨어 및 응용 Vol.37 No.10

콘콜릭 테스트는 높은 테스트 커버리지를 달성하기 위해 실제 프로그램 수행과 심볼릭 수행을 결합하여 테스트 데이터를 생성한다. CREST는 콘콜릭 테스팅을 구현한 대표적인 open-source인 테스트 도구이다. 그러나 현재 CREST는 기본적으로 프로그램의 모든 가능한 실행 경로들을 탐색하는 것을 목적으로 한다. 이 때문에 특정 분기 또는 블록만을 테스트하는 경우에는 비효율적일 수 있다. 이 논문에서는 프로그램 상의 한 분기 또는 블록을 주고 이를 실행할 수 있는 테스트 데이터를 생성하는 목적 지향 콘콜릭 테스트 방법을 제안한다. Concolic testing generates test data by combining concrete program execution and symbolic execution to achieve high test coverage. CREST is a representative open-source test tool implementing concolic testing. Currently, however, CREST aims at exploring all possible execution paths. In case of testing a specific branch or block, thus, it can be ineffective. This paper suggests a goal-oriented concolic testing that generates test data to execute a given branch or block.

항주파의 파봉에 대한 연구

이병욱(Byeong Wook Lee),이창훈(Changhoon Lee) 한국해안해양공학회 2016 한국해안해양공학회 논문집 Vol.28 No.1

항주파 파봉의 위치를 예측하는 Kelvin(1887)의 이론해는 심해에서만 적용 가능한 한계가 있다. 최대파향각을 예측하는 Havelock(1907)의 이론해는 모든 수심에서 적용 가능하지만 파향각에 따라 다르게 나타나는 파봉의 위치를 예측하지 못하는 한계가 있다. 본 연구에서 항주파의 분산관계식을 온전하게 이용하여 모든 수심에 적용 가능한 항주파 파봉식을 개발하고, 이 식을 이용하여 항주파의 최대파향각을 예측하였다. FLOW-3D를 이용하여 Johnson(1958)의 수리모형실험을 수치적으로 재현한 후 본 연구에서 제안하는 최대파향각의 이론해가 모든 수심에서 수치해, 수리실험결과와 유사함을 확인하였다. 여러 조건에서 항주파를 수치적으로 재현한 후 파봉선 간의 거리를 측정하여 이론해와 비교하였다. 그 결과 선박의 속도가 √gh 보다 작은 경우 이론해와 유사하였다. 선박의 속도가 √gh 보다 큰 경우 첫 번째 항주파의 거리를 결정하는 상수 C1은 0에 가까운 값이었고 첫 번째 항주파를 제외한 경우 이론해와 유사하였다. Kelvin’s (1887) theory that predicts position of ship wave crest can be applied only in deep water. Havelock’s (1907) theory that predicts cusp locus angle can be applied in whole water depths but cannot predict the position of ship wave crest. In this study, using the linear dispersion fully, we develop the equations to predict ship wave crest in whole water depths and, using the developed equations, we predict cusp locus angle. We simulate ship wave propagation using FLOW-3D in the condition of Johnson’s (1985) hydraulic experiment and find that the cusp locus angles predicted by the present theory are close to numerical results of FLOW-3D and hydraulic experimental data. We also simulate for various conditions and compare numerical results of distances between adjacent wave crests and values predicted by the present theory. For Froude number less than unity, the numerical results are close to the values predicted by the theory. For Froude number greater than unity, the constant value of C1 which determines the distance between the ship and the first ship wave crest is almost equal to zero and the numerical results of distances between adjacent ship waves excluding the first ship are close to the values predicted by the theory.

수치모의를 이용한 원형위어의 월류흐름 특성 해석

김대근 대한상하수도학회 2016 상하수도학회지 Vol.30 No.2

The present study used the hydrodynamic numerical model, with the Reynolds-averaged Navier–Stokes equations (RANS) as its governing equations, to analyze overflow characteristics such as the discharge coefficient of circular-crested weir and the flow velocity and pressure distribution of weir crest. The simulation results well reproduced the overflow characteristics of the overfall of circular-crested weir both qualitatively and quantitatively. As for the discharge coefficient, rational results were yielded by the discharge coefficient equation proposed by Hager(1985) in the H1/Rb< 0.58 and by the discharge coefficient equation proposed by Samani and Bagheri(2014) in the H1/Rb> 0.58, respectively. Because most existing discharge coefficient equations were developed by disregarding the effects of the approach velocity, when they are applied, it is necessary to evaluate the effects of the approach velocity on the overflow head beforehand.

직립식 방파제의 마루높이 산정을 위한 최대월파량에 대한 신뢰성 해석

이철응(Lee, Cheol-Eung) 한국해안해양공학회 2011 한국해안해양공학회 논문집 Vol.23 No.2

개별파 최대월파량 개념을 이용하여 직립식 방파제의 마루높이를 산정할 수 있는 신뢰성 해석 모형이 개발되었다. 입사파랑이 작용하는 시간 동안 월파되는 파랑의 개수와 상대마루높이 그리고 평균월파유량의 함수로 정의되는 개별파 최대월파량과 그 허용치를 이용하여 신뢰함수를 수립하였다. 상대적으로 다른 불확실성을 갖는 관련 경험계수들을 확률변수로 고려하여 신뢰성 해석을 수행할 수 있는 Level III MCS 기법을 제시하였다. 장봉파 및 단봉파 조건에서 입사파향, 직립식 방파제의 구조형식 그리고 개별파 최대월파량의 허용수준을 변화시키면서 상대 마루높이에 따른 파괴확률을 산정하였다. A reliability analysis model is developed for evaluating the crest freeboard of vertical breakwaters based on the concepts of maximum overtopping volume of individual wave. A reliability function is formulated by defining the margin of admissible overtopping volume and maximum overtopping volume that is depend on the number of overtopping waves, dimensionless crest freeboard, and mean overtopping discharge. In addition, Level III MCS technique is straightforwardly suggested by which the related empirical parameters to reliability function can be considered to be random variables with the wide range of different uncertainties. It can be possible to calculate the probabilities of failure according to the relative crest freeboard with the variations of the incident wave directions, the structural types of vertical breakwaters, and admissible overtopping volumes in conditions of the long and short crested-waves.