• Journal of applied mathematics & informatics
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• 제28권5_6호
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• pp.1379-1393
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• 2010

In this paper, a stage-structured predator prey model (stage structure on prey) with two discrete time delays has been discussed. The two discrete time delays occur due to maturation delay and gestation delay. Linear stability analysis for both non-delay as well as with delays reveals that certain thresholds have to be maintained for coexistence. Numerical simulation shows that the system exhibits Hopf bifurcation, resulting in a stable limit cycle.

• 충청수학회지
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• 제36권1호
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• pp.39-53
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• 2023

In this paper, we consider a delayed ratio-dependent predator-prey reaction-diffusion system with homogenous Neumann boundary conditions. We study the existence of nonnegative solutions and the stability of the nonnegative equilibria to the system. In particular, we provide a sufficient condition for the positive equilibrium to be globally asymptotically stable.

• Neonatal Medicine
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• 제18권2호
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• pp.310-319
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• 2011

목적: ELBWI의 출생과 생존율이 증가함에 따라 그들의 삶의 질의 향상을 위해 신경학적 발달을 예측 및 평가하고 재활 치료를 통해 발달 지연을 최소화하기 위한 많은 연구가 이루어지고 있다. 뇌 손상의 평가 및 신경학적 발달을 예측하기 위하여 뇌 MRI의 촬영이 많이 이루어지고 있고, 연구를 통해 다양한 프로토콜이 개발되고 있다. 저자들은 Childs 등이 제안한 뇌 성숙도를 점수화 하는 방법을 통해 ELBWI의 주산기에 발생하는 위험 인자와 뇌성숙의 관계, 뇌 성숙과 신경학적 발달 지연과의 관계에 대해 확인하고자 한다. 방법: 교정 주령 만삭 근처에 뇌 MRI를 시행한 ELBWI 124명을 대상으로 의무 기록을 후항적으로 분석하여 주산기적 위험인자를 확인하였고, 뇌 MRI에서 뇌 성숙도를 점수화(TMS) 하고, 동반 되는 이상 소견을 판독하였으며, BSID III를 시행하여 신경학적 발달에 대한 평가를 하였다. 주산기적 위험인자와 TMS의 관계, 뇌 MRI에서 관찰 되는 이상 소견과 TMS의 관계, TMS와 BSID III 결과의 관계에 대한 분석을 하였다. 결과: 대상 환자의 평균 출생 재태 주령은 27.1${\pm}$2.1주, 평균 출생 체중은 781.5${\pm}$143.9 g 이었다. 뇌 성숙도 점수의 평균은 10.8${\pm}$2.0점이었다. 주산기적 위험 인자와의 관계 분석에서는 MRI 검사 당일의 PMA만이 통계학적으로 유의한 관계를 보였고 (P<0.001), BSID III에서 확인되는 신경학적 발달 지연이나 뇌 MRI에서 이상 소견과 뇌 성숙도 점수 간에는 통계학적으로 유의한 상관관계가 없었다. 결론: Conventional 뇌 MRI에서 뇌 성숙도를 평가하여 신경학적 발달을 예측하고, 뇌 성숙에 영향을 주는 주산기적 위험인자를 찾고자 하였으나 MRI 검사 당일의 PMA 외에는 통계학적으로 의미 있는 결과가 없었다. 하지만 수초화 등의 뇌 성숙의 정도가 신경학적 발달에 영향을 줄 것으로 추측되므로 향후 더 다양한 교정 주수에 촬영된 영상과 여러 임상 환자군의 영상에 대한 분석 및 BSID III 등 신경학적 발달 검사와의 관계에 대한 연구가 필요하다.

• 한국연초학회지
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• 제9권2호
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• pp.59-68
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• 1987

황색종 잎담배의 성숙과 노쇠 (이식후 50일부터 106일까지 )에 따른 생엽중 전분, 전당, 니코틴 및 전질소의 함량 변화와 이들 성분간의 관계를 조사한바, 전분함량은 두 품종 모두 각 엽위에서 성숙함에 따라 증가하였으나 노쇠함에 따라 감소하였다. 전질소 함량은 성숙함에 따라 감소하였으나 니코틴 함량 은 점점 증가하였다. 전당 함량은 성숙함에 따라 감소하는 경향이었다. 전분 함량은 전질소 함량과는 부의 상관을 보였으나 니코틴 함량과는 정의 상관이 인정되었다. 전질소 함량과 니코틴 함량은 부의 상관이 인정되었다. 그러므로 수확기를 관행보다 5-7일 늦추는 것은 건엽에서 환원당과 니코틴의 비를 더 좋게 하는 방법일 것이다.

• Restorative Dentistry and Endodontics
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• 제46권1호
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• pp.3.1-3.14
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• 2021

Objectives: This study aimed to evaluate the interface between a calcium silicate cement (CSC), Biodentine and dental adhesives in terms of sealing ability. Materials and Methods: Microleakage test: 160 standardized class II cavities were prepared on 80 extracted human molars. The cavities were filled with Biodentine and then divided into 2 experimental groups according to the time of restoration: composite resin obturation 15 minutes after Biodentine handling (D0); restoration after 7 days (D7). Each group was then divided into 8 subgroups (n = 5) according to the adhesive system used: etch-and-rinse adhesive (Prime & Bond); self-etch adhesive 2 steps (Optibond XTR and Clearfil SE Bond); self-etch adhesive 1 step (Xeno III, G-aenial Bond, and Clearfil Tri-S Bond); and universal used as etch-and-rinse or self-etch (ScotchBond Universal ER or SE). After thermocycling, the teeth were immersed in a silver nitrate solution, stained, longitudinally sectioned, and the Biodentine/adhesive percolation was quantified. Scanning electron microscopic observations: Biodentine/adhesive interfaces were observed. Results: A tendency towards less microleakage was observed when Biodentine was etched (2.47%) and when restorations were done without delay (D0: 4.31%, D7: 6.78%), but this was not significant. The adhesives containing 10-methacryloyloxydecyl dihydrogen phosphate monomer showed the most stable results at both times studied. All Biodentine/adhesive interfaces were homogeneous and regular. Conclusions: The good sealing of the CSC/adhesive interface is not a function of the system adhesive family used or the cement maturation before restoration. Biodentine can be used as a dentine substitute.

• Clinical and Experimental Pediatrics
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• 제53권11호
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• pp.931-935
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• 2010

Juvenile idiopathic arthritis (JIA) is comprised of a heterogeneous group of several disease subtypes that are characterized by the onset of arthritis before the age of 16 years and has symptoms lasting at least 6 weeks. The previous classification of JIA included seven different categories, whereas its current classification was compiled by the International League of the Association for Rheumatology, and replaced the previous terms of "juvenile chronic arthritis" and "juvenile rheumatoid arthritis," which were used in Europe or North America, respectively, with the single nomenclature of JIA. As mentioned above, JIA is defined as arthritis of unknown etiology that manifests itself before the age of 16 years and persists for at least 6 weeks, while excluding other known conditions. The clinical symptoms of JIA can be quite variable. Several symptoms that are characteristic of arthritis are not necessarily diagnostic of JIA and may have multiple etiologies that can be differentiated with careful examination of patient history. The disease may develop over days or sometimes weeks, thereby making the diagnosis difficult at the time of presentation. To make a clinical diagnosis of JIA, the first step is to exclude arthritis with known etiologies. Of note, late treatment due to excessive delay of diagnosis can cause severe damage to joints and other organs and impair skeletal maturation. Therefore, early detection of JIA is critical to ensure prompt treatment and to prevent long-term complications including the likelihood of disability in childhood.

• 한국언어정보학회지:언어와정보
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• 제5권2호
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• pp.39-55
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• 2001

This paper investigates the idiosyncratic understanding of universal quantifiers such as every, each or all by young children at the ages of 4 to 7, and argues that the phenomenon is explicable in terms of the maturation of both the cognitive system and the linguistic system. Evidence for this dual explanation comes from the fact that the visual input, a picture, plays a key role in determining the children's conceptual representation, suggesting the need for the central integration of visual and linguistic elements; and from the fact that a quantifier in the linguistic input has an intrinsic property, i.e. a <+focus> feature. I have tried to explain the nature of the cognitive factors in terms of the function of the central system, suggesting a modified form of Smith & Tsimpli's (1995) yersion of Fodor's (1983) modularity hypothesis. The categorial status of the quantifier in the children's interpretation is considered, focusing on the movement of that quantifier out of its own extended projection to FP. It is claimed that children initially treat quantifiers as modifiers, rather than functional heads, and that the phenomenon of quantifier spreading by children can be attributed to delay in the development of the relevant functional category, i.e., DP (or QP), in language acquisition.

• Clinical and Experimental Pediatrics
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• 제61권12호
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• pp.403-406
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• 2018

Floating-Harbor syndrome is a rare autosomal dominant genetic disorder associated with SRCAP mutation. To date, approximately 50 cases of Floating-Harbor syndrome have been reported, but none have been reported in Korea yet. Floating-Harbor syndrome is characterized by delayed bony maturation, unique facial features, and language impairment. Here, we present a 6-year-old boy with a triangular face, deep-set protruding eyes, low-set ears, wide nose with narrow nasal bridge, short philtrum, long thin lips, clinodactyly, and developmental delay that was transferred to our pediatric clinic for genetic evaluation. He showed progressive delay in the area of language and cognition-adaption as he grew. He had previously undergone chromosomal analysis at another hospital due to his language delay, but his karyotype was normal. We performed targeted exome sequencing, considering several syndromes with similar phenotypes. Library preparation was performed with the TruSight One sequencing panel, which enriches the sample for about 4,800 genes of clinical relevance. Massively parallel sequencing was conducted with NextSeq. An identified variant was confirmed by Sanger sequencing of the patient and his parents. Finally, the patient was confirmed as the first Korean case of Floating-Harbor syndrome with a novel SRCAP (Snf2 related CREBBP activator protein) mutation (c.7732dupT, p.Ser2578Phefs*6), resulting in early termination of the protein; it was not found in either of his healthy parents or a control population. To our knowledge, this is the first study to describe a boy with Floating-Harbor syndrome with a novel SRCAP mutation diagnosed by targeted exome sequencing in Korea.

• 한국작물학회지
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• 제25권4호
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• pp.1-9
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• 1980

To determine the optimum harvest time of recent rice varieties from Indica/Japonica remote crosses, leading varieties Suweon 264 and Milyang 23 were tested for the changes in dry matter weight and moisture content of grain, shattering, shelling ratio, milling ratio, and apparant physical quality during grain development at 5 day-intervals from 20 days to 55 days after heading. The results are summarized as follows: 1. Grain weight (dry matter) reached its maximum (physiological maturity) at 30 days after flowering (DAF) in Suweon 264, and at 35 days in Milyang 23, and thereafter it did not change significantly until 55 DAF. 2. Time course of decrease in grain moisture content (Y, %) during maturation (X, DAF) consisted of two linear phases, i.e. a fast and a slow period: Y=68.245-1.33X until 34DAF, and Y=23.025-0.470X until 55DAF after 34DAF in Suweon 264; Y=73.62-1.634X until 24.5DAF, and Y=33.59-0.570X until 55DAF after 24.5DAF in Milyang 23. Two varieties showed the same grain moisture content of 28% (wet basis) at physiological maturity in spite of the distinct differences in the heading date, time of physiological maturity and thereby ripening climate. 3. Force to shatter a grain ranged about 90 to 100g in Milyang 23, and about 200 to 250g in Suweon 264 and in a Japonica variety, Jinheung. The force, however, did not change significantly with harvest time from 35DAF to 50DAF. 4. The changes in the ratios of shelling, milling, broken rice and tinted rice with harvest time were insignificant during a period from 35DAF to 55DAF. However, ratios of green rice and white belly rice decreased significantly with delay in harvest time during 10 days after physiological maturity. 5. The best time of harvest for maximum yield and good quality is thought to be 10 days after physiological maturity, and grain moisture content at this time was about 20% on wet basis.

• 한국발생생물학회지:발생과생식
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• 제18권3호
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• pp.139-143
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• 2014

Different with other fishes, the guppies (Poecilia reticulata) is ovoviviparity, which retain their fertilized eggs within the follicle throughout gestation. The synchronously growing diplotene oocytes store nutrients in droplets and yolk, before their maturation and fertilization. The lecithotrophic strategy of development entails the provisioning of embryos with resources from the maternal yolk deposit rather than from a placenta, it allows the extracorporeal culture of guppy embryo. Studies on their early development of live bearers like the guppy including lineage tracing and genetic manipulations, have been limited. Therefore, to optimize conditions of embryo in vitro culture, explanted embryos from pregnant females were incubated in embryo medium (L-15 medium, supplemented with 5, 10, 15, 20% fetal bovine serum, respectively). We investigated whether the contents of FBS in vitro culture medium impact the development of embryos, and whether they would hatch in vitro. Our study found that in 5% of FBS of the medium, although embryos developed significantly slower in vitro than in the ovary, it was impossible to exactly quantify the developmental delay in culture, due to the obvious spread in developmental stage within each batch of eggs, and embryos can only be maintained until the early-eyed. And although in culture with 20% FBS the embryos can sustain rapid development of early stage, but cannot be cultured for the entire period of their embryonic development and ultimately died. In the medium with 10% and 15% FBS, the embryos seems well developed, even some can continue to grow after follicle ruptures until it can be fed. We also observed that embryonic in these two culture conditions were significantly different in development speed, in 15% it is faster than 10%. But 10% FBS appears to be more optimizing condition than 15% one on development process of embryos and survival rate to larvae stage.