• Clinical and Experimental Reproductive Medicine
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• 제39권3호
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• pp.95-106
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• 2012

It has been revealed that multiple cohorts of tertiary follicles develop during some animal estrous cycle and the human menstrual cycle. To reach developmental competence, oocytes need the support of somatic cells. During embryogenesis, the primordial germ cells appear, travel to the gonadal rudiments, and form follicles. The female germ cells develop within the somatic cells of the ovary, granulosa cells, and theca cells. How the oocyte and follicle cells support each other has been seriously studied. The latest technologies in genes and proteins and genetic engineering have allowed us to collect a great deal of information about folliculogenesis. For example, a few web pages (http://www.ncbi.nlm. nih.gov; http://mrg.genetics.washington.edu) provide access to databases of genomes, sequences of transcriptomes, and various tools for analyzing and discovering genes important in ovarian development. Formation of the antrum (tertiary follicle) is the final phase of folliculogenesis and the transition from intraovarian to extraovian regulation. This final step coordinates with the hypothalamic-pituitary-ovarian axis. On the other hand, currently, follicle physiology is under intense investigation, as little is known about how to overcome women's ovarian problems or how to develop competent oocytes from in vitro follicle culture or transplantation. In this review, some of the known roles of hormones and some of the genes involved in tertiary follicle growth and the general characteristics of tertiary follicles are summarized. In addition, in vitro culture of tertiary follicles is also discussed as a study model and an assisted reproductive technology model.

• Structural Engineering and Mechanics
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• 제41권1호
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• pp.25-41
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• 2012

Kriging surrogate model provides explicit functions to represent the relationships between the inputs and outputs of a linear or nonlinear system, which is a desirable advantage for response estimation and parameter identification in structural design and model updating problem. However, little research has been carried out in applying Kriging model to crack identification. In this work, a scheme for crack identification based on a Kriging surrogate model is proposed. A modified rectangular grid (MRG) is introduced to move some sample points lying on the boundary into the internal design region, which will provide more useful information for the construction of Kriging model. The initial Kriging model is then constructed by samples of varying crack parameters (locations and sizes) and their corresponding modal frequencies. For identifying crack parameters, a robust stochastic particle swarm optimization (SPSO) algorithm is used to find the global optimal solution beyond the constructed Kriging model. To improve the accuracy of surrogate model, the finite element (FE) analysis soft ANSYS is employed to deal with the re-meshing problem during surrogate model updating. Specially, a simple method for crack number identification is proposed by finding the maximum probability factor. Finally, numerical simulations and experimental research are performed to assess the effectiveness and noise immunity of this proposed scheme.

• 한국육종학회지
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• 제40권3호
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• pp.215-222
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• 2008

Fifty-two Korean japonica rice cultivars were analyzed for leaf blast resistance and genotyped with 4 STS and 26 SSR markers flanking the specific chromosome sites linked with blast resistance genes. In our analysis of resistance genes in 52 japonica cultivars using STS markers tightly linked to Pib, Pita, Pi5(t) and Pi9(t), the blast nursery reaction of the cultivars possessing the each four major genes were not identical to that of the differential lines. Eight of the 26 SSR markers were associated with resistant phenotypes against the isolates of blast nursery as well as the specific Korean blast isolates, 90-008 (KI-1113), 03-177 (KJ-105). These markers were linked to Pit, Pish, Pib, Pi5(t), Piz, Pia, Pik, Pi18, Pita and Pi25(t) resistance gene loci. Three of the eight SSR markers, MRG5836, RM224 and RM7102 only showed significantly associated with the phenotypes of blast nursery test for two consecutive years. These three SSR markers also could distinguish between resistant and susceptible japonica cultivars. These results demonstrate the usefulness of marker-assisted selection and genotypic monitoring for blast resistance of rice in blast breeding programs.

• 대한교통학회지
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• 제28권2호
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• pp.135-150
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• 2010

본 논문의 목적은 민간투자사업의 계약에서 가장 중요하고 핵심적인 계약이라 할 수 있는 실시협약 사례를 수집하고 분석함으로써 협상을 통해 결정된 사업 수익률의 결정요인들이 무엇이며, 실시협약에서 포함된 제도 및 정책에 따라 수익률이 어떻게 반영되었는지를 파악하는 것이다. 수익률이 사업성을 판단할 수 있는 지표라면, 가산금리는 대출 원리금의 회수의 위험정도를 판단할 수 있는 지표라 할 수 있다. 실증분석에서 사용된 데이터는 1995년부터 2008년까지 실시협약을 체결하였거나 협상이 완료된 사업의 실시협약 및 재무모델 75건을 대상으로 조사하였다. 종속변수는 세후경상수익률 및 재무모델에서 제시하고 있는 장기차입이자율의 가산금리로 하였으며, 독립변수는 사업절차에 따른 변수, 사업성에 관련된 변수, 재무적 성격에 따른 변수, 실시협약 문건에 관련된 변수, 정부 정책에 관련된 변수 등으로 하였다. 분석결과 수익률에 대해서는 재무적 투자자의 출자비율, 국가관리사업인 경우, 최소운영수입보장 조항 등에 영향을 미치는 것으로 분석되었으며, 가산금리의 경우에는 재무적 투자자의 출자비율, 국가관리사업, 부대사업의 유무 등이 결정에 영향을 미치는 것으로 분석되었다.