• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1249-1254
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• 2005

The aim of this study was to determine the effect of maturity stage on the nutritive value of wild mustard straw in terms of chemical composition, in situ, in vitro dry matter degradability and calculated ME. The nutritive values of wild mustard, Sinapsis arvensis hays harvested at three stages were evaluated by chemical composition, in vitro gas production and in situ dry matter degradation methods. Gas production or dry matter (DM) degradation were determined at 0, 3, 6, 12, 24, 48, 72 and 96 h and their kinetics were described using the equation p = a+b(1-e$^{-ct}$). Maturity had a significant effect on both the chemical composition and degradability of wild mustard. Neutral detergent fibre (NDF) and acid detergent fibre (ADF) (p<0.001) increased with increasing maturity whereas the crude protein (CP) (p<0.001) decreased. The gas produced after 96 h incubation ranged between 64.7 and 81.5 ml per 0.200 g of dry matter. The gas production (ml) at all incubation times and estimated parameters decreased with increasing maturity of wild mustard. The gas production at all incubation times and estimated parameters (a, b (a+b), metabolizable energy (ME) and organic matter digestibility (OMD)) were negatively correlated with NDF and ADF. The DM disappearance after 96 h incubation ranged between 50.8 and 76.1%. The in situ DM disappearance at all incubation times and estimated parameters decreased with increasing maturity of wild mustard. The in situ dry matter disappearance at all incubation times and some estimated parameters (c, a, b and effective dry matter degradability (EDMD)) were negatively correlated with NDF and ADF but positively correlated with CP. The nutritive value of wild mustard continually changed as it matured. Wild mustard, harvested at the proper stage of maturity offers considerable potential as a high quality forage for ruminants during the winter feeding period. The present study showed that if higher quality forage is an objective, wild mustard should be harvested at the early flowering stage.

• The korean journal of orthodontics
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• v.39 no.2
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• pp.120-129
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• 2009

Objective: To estimate dental maturity using the Demirjian Index for the mandibular third molar and investigate the relationships between dental maturity and skeletal maturity among growing children. Methods: The samples were derived from panoramic, lateral cephalometric and hand-wrist radiographs of 270 female subjects registered as patients at the orthodontic department, dental hospital, Yonsei University. Dental maturity [Demirjian Index (DI)] and skeletal maturity [skeletal maturation indicators (SMIs)] and cervical vertebrae maturation indicators (CVMIs)] were estimated from these radiographs. Results: There was a significant correlation (r = 0.64) between SMIs and DI, and a similar correlation (r = 0.59) was observed between CVMIs and DI (p < 0.001). If DI was above Stage E, then the SMI was above Stage 10 and the CVMI was above Stage 5. There was a weak correlation (r = 0.26) between age at menarche and DI (p < 0.001). There was no significant difference in DI among Class I, II or III malocclusions. Conclusions: Dental maturity evaluation using the mandibular third molar will be an adjunctive tool in combination with cervical vertebrae and hand-wrist maturity evaluations.

• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.3
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• pp.225-232
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• 2014

The purpose of this study was to compare skeletal maturity index and dental developmental stages based on skeletal malocclusion. A total of 192 patients (89 male and 103 female) between 6 to 14 years old were selected for this study and underwent cephalograms, panorama radiographs, and hand-wrist radiographs. Any syndromic cases were excluded. Selected clinical parameters were dichotomised for statistical analysis. Chi-square, logistic regression analysis, and independent t-tests were used for the statistical evaluation. Canine, first molar, and second molar calcification were significantly associated with skeletal maturity in the logistic regression model (p < 0.05). In addition, patients who had higher skeletal maturity index were 11.43 times more likely to be female than those who had lower skeletal maturity index (p < 0.001). The patients with skeletal class II malocclusion displayed significantly higher dental developmental stage in canines, first premolars, first molars, and second molars than the patients with class III malocclusion (p < 0.05). The dental developmental stage of the patients was significantly associated with skeletal maturity. In addition, there was a significant difference between class II and class III malocclusion with some types of tooth calcification.

• The Korean Journal of Malacology
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• v.16 no.1_2
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• pp.35-41
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• 2000

We investigated the gonad index (GI), gonadal development, the reprodutive cycle and first sexual maturity of the venus clam, Cyclina sinensis by histological observation. Samples were collected from the intertidal zone of Komso Bay, Chollabuk-do, west coast of Korea, from April 1998 to March 1999. This clam is dioecious and oviparous. Monthly changes in the gonad index (GI) showed a similar pattern to the reproductive cycle. Ripe oocytes are about 90-100 ㎛ in diameter. The spawning period was between early July to September, and the main spawning occurred between July and August when the sea water temperature was over 20$\^{C}$ The reproductive cycle of this species can be divided into five successive stages: early active stage (February to April), late active stage (March to June), ripe stage (April to August), partially spawned stage (July to October), and spent / inactive stage (September to February). Percentages of first sexual maturity of female and male clams measuring 26.1-30.0 ㎜ in shell length were 53.3% and 62.5%, respectively, and 100% for the clams > 41.0 ㎜. It is assumed that both sexes begin reproduction at about two years age.

• The Korean Journal of Malacology
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• v.21 no.1
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• pp.1-11
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• 2005

Reproductive cycle, first sexual maturity, spawning amount related with the size and spawning interval in female Ruditapes philippinarum were investigated by histological observation and the analysis of morphometric data during artificial spawning induction. Ruditapes philippinarum is dioecious and oviparous. The reproductive cycle of this species can be subdivided into five successive stages: early active stage (January to March), late active stage (February to May), ripe stage (April to August), partially spawned stage (May to October), and spent/inactive stage (August to February). The spawning period was once a year between May and early October, and the main spawning occurred between July and August when seawater temperature was approximately $20^{\circ}C$. Percentages of first sexual maturity of female clam of 15.1-20.0 mm in shell length were 56.3%, and 100% for the clams > 25.1 mm. The mean number of the spawned eggs increased with the increase of size classes (shell length). In case of spawning induction by the same size class, the number of spawned eggs were gradually decreased with the increase of spawning frequencies (the first, second, and third spawnings). In the experiments of artificial spawning induction during the spawning season, the interval of each spawning was estimated to be 15-17 days (average 16.5 days).

• The Korean Journal of Malacology
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• v.21 no.2 s.34
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• pp.81-93
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• 2005

Reproductive cycle with the gonadal phases, first sexual maturity, artificial spawning amount by the size and spawning interval of the hard clam, Meretrix lusoria were investigated by histological observations and morphometric data by artificial spawning induction. Meretrix lusoria is dioecious and oviparous. The reproductive cycle of this species can be classified into five successive stages: early active stage (January to March), late active stage (February to May), ripe stage (April to August), partially spawned stage (June to September), and spent/inactive stage (September to February). The spawning period was from June to September, and the main spawning occurred between July and August when the seawater temperature exceeds over $20^{\circ}C$. Percentage of first sexual maturity of female and male clams ranging from 40.0 to 45.0 mm in shell length was over 50%, and all clams over 50.0 mm in shell length sexually matured. Female and male clams ranging from 40.0 to 45.0 mm in shell length are considered to be two years old. Therefore, we assume that the hard clams of both sexes begin reproduction from two years of age. The mean number of the spawned eggs increased with the increase of size (shell length) classes. In case of artificial spawning induction, the number of spawned eggs from the clams of a sized class was gradually decreased with the increase of the number of the spawning frequencies (the first, second, and third spawnings). In the experiments of artificial spawning induction during the spawning season, the interval of each spawning was estimated to be 15-18 days (average 17 days).

• The Korean Journal of Malacology
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• v.21 no.2 s.34
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• pp.95-105
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• 2005

Gonadosomatic index, reproductive cycle, spermatogenesis and first sexual maturity of Chlamys farreri were investigated by cytological and histological observations, from January 1998 to December 1999. The gonadosomatic index (GSI) rapidly increased in April and reached a maximum in May when seawater temperature rapidly increase. Then the GSI gradually decreased from June to August when spawning occur. Accordingly, monthly changes in the GSI in males coincide with the reproductive cycle. The spermatozoon of Chlamys farreri is the primitive type found in external fertilization species. The head of the spermatozoon is approximately $2.75{\mu}m$ in length including the acrosome measuring about $0.50{\mu}m$ in length, and its tail was approximately $20{\mu}m$, the axoneme of the tail flagellum consists of nine pairs of microtubules at the periphery and a pair at the center. Five spherical mitochondria around the centriole (the satellite body) appear in the middle piece of the sperm. The spawning period was from June to August and the main spawning occurs from July to August when seawater temperatures are greater than $20^{\circ}C$ The reproductive cycle of this species can be categorized into five successive stages; early active stage (January to March), late active stage (March to April), ripe stage (April to August), partially spawned stage (June to August), and spent/inactive stage (August to January). Over 50% of male scallops attained first sexual maturity between 50.0 and 60.0 mm in shell height, and 100% of those over 60.0 mm in shell height achieved maturity. Accordingly, we assume that male individuals begin reproduction at three years of age.

• Health Policy and Management
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• v.18 no.4
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• pp.85-110
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• 2008

In this study, we explore the long-term demand forecasting of high-price medical equipments based on logistic and Bass diffusion model. We analyze the specific pattern of each equipment's diffusion curve by interpreting the parameter estimates of Bass diffusion model. Our findings are as follows. First, ultrasonic imaging system, CT are in the stage of maturity and so, the future demands of them are not too large. Second, medical image processing unit is between growth stage and maturity stage and so, the demand is expected to increase considerably for two or three years. Third, MRI is in the stage of take-off and Mammmography X-ray system is in the stage of maturity but, estimates of the potential number of adopters based on logistic model is considerably different to that based on Bass diffusion model. It means that additional data for these two equipments should be collected and analyzed to obtain the reliable estimates of their demands. Fourth, medical image processing unit have the largest q value. It means that the word-of-mouth effect is important in the diffusion of this equipment. Fifth, for MRI and Ultrasonic system, q/p values have the relatively large value. It means that collective power has an important role in adopting these two equipments.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.2
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• pp.83-96
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• 2011

The open space of apartment complex has changed diversely according to construction periods which were divided into the introduction stage (the 1980s), the development stage (the 1990s), and the maturity stage (after 1999). This study set out to analyze the periodic changes of visual characteristics and preference with the open space of apartment complexes in Cheongju City. For analysis of visual characteristics and preference, nineteen adjectives that were determined to sufficiently express the feeling of the open space of apartment complex. The results are as follows. As for adjective image assessment by using descriptive statistics, favorable images were shown in complexes of maturity stage phase that were constructed after the liberalization of apartment sale in 1999. These results may be caused both by quantitative increase and diversification of materials in planting and landscaping furniture and by nature-friendly designing. The results of factor analysis by Varimax rotation method showed that common variance was 73.9%, which indicates higher explanation. The nineteen adjectives could be divided into three factors, 'pleasantness factor,' 'negative factor,' and 'irregular factor.' Visual preference was analysed by using Least significant Difference (LSD) by analysis of variance : complexes of maturity stage phase that were constructed according to the liberalization of apartment sale in 1999 were highest in assessment. The correlation between view preference and adjective images was analyzed by multiple regression analysis, and 'feeling like walking,' 'well-arranged,' 'beautiful,' 'friendly,' and 'clean' (in order) were adjective images that most affected the preference. As for the analysis of the correlation between visual preference and physical components of view, the preference increased as the rate of pavement and greens was higher, while it decreased as size of building was larger. Therefore, backgrounds of walking and greens had strong effects on the preference.

• The korean journal of orthodontics
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• v.25 no.4
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• pp.415-423
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• 1995

In order to investigate the relationship between the menarche and the bone maturity of growing girls, the author interviewed about the date of menarche of 70 girls and assessed their bone maturity by hand-wrist radiographs. The results and conclusion were as iollows ; 1. The mean menarcheal age was $12.04{\pm}0.82$ year. 2. There was significant correlation between the time interval after menarche and the ossification stage. 3. The skeletal maturation level at menarche was stage SMI 7 and SMI 8. 4. There was statistically different among the time intervals after menarche according to the ossification stage. 5. The epiphyseal union of radius began about 2 years after menarche. According to this study, the probability of clinical use can be accepted in some range. In another words, skeletal age can be predicted by just interviewing the date and time interval of menarche without hand-wrist radiograph, also, with this information, the level of maxillofacial growth can be assessed.