• The Korean Journal of Malacology
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• v.22 no.2
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• pp.175-182
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• 2006

Artificial induction of maturation by heating of the ark shell, Scapharca broughtonii (Schrenck) broodstock was investigated from 10th March to 21th May in 2004. Maturity at the fixed water temperature group of $23^{\circ}C$ was 60.5％, and it was the highest in maturity among experimental groups cultured for seven weeks. The proportions of organism surviving to start of S. broughtonii in the raised water temperature experimental groups (20 and $23^{\circ}C$) were over 90.5％, as similar to the control group (natural water temperature, 84.8％). But, the proportions of organism surviving to start of S. broughtonii in the fixed water temperature experimental groups (20, 23, and $26^{\circ}C$) were decreased with the increasing of the water temperature. In the fixed water temperature experimental groups of $26^{\circ}C$, the survival was 18.1％. Base on these results, the fixed water temperature of $20^{\circ}C$ (accumulated water temperature; $1,295^{\circ}C$) was the best condition for artificial induction of sexual maturation.

• Journal of Korean Library and Information Science Society
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• v.51 no.4
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• pp.101-119
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• 2020

The study aims to understand major topics and concerns of gender identity-related questions expressed by the users of the NAVER social Q&A site. To achieve this goal, we analyzed 2,120 questions created from 2010 to 2018 using natural language- and information retrieval-based methods. Results indicated that the major topics discussed by the users include interpersonal relationships, doubts about gender identity, sexual orientation, feelings and relationships, and concerns about gender identity. In addition, users mainly expressed concerns regarding general issues of gender identity; sexual orientation; negative cognition about gender identity; confession, coming-out, homosexuality; future, heterosexual relationships, military enlistment; and causes of gender identity confusion. The present study effectively derives information needs from real-world concerns about sexual identity by employing topic modeling techniques, and by comparing the advantages of exact match and tf-idf-based information retrieval methods extends methodology of Library and Information Science. Further, it has contributed to the academic maturity of the study of information behavior by observing the information needs or information-seeking behaviors of online community users with specific interests.

• The korean journal of orthodontics
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• v.21 no.2 s.34
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• pp.341-351
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• 1991

Dental maturity is one of the index of physiological maturity indicators. To investigate the relationship between dental maturity and chronological age, the author took the orthopantomograms of 984 students, aged 7 through 17 years, having normal occlusion. The orthopantomograms were examined and calcification degree of each tooth on the left side was rated according to the method described by Demirjian. On the basis of findings of this study, the following results were obtained. 1. The root completion periods of mandibular permanent teeth were as follows; Central Incisor M $8.32{\pm}1.03\;years$ F $7.96{\pm}1.04\;years$ Lateral Incisor M $9.40{\pm}1.30\;years$ F $9.01{\pm}0.90\;years$ Canine M $12.81{\pm}1.24\;years$ F $11.42{\pm}0.94\;years$ 1st Premolar M $12.76{\pm}1.74\;years$ F $12.19{\pm}1.33\;years$ 2nd Premolar M $13.31{\pm}1.88\;years$ F $12.88{\pm}1.49\;years$ 1st Molar M $9.60{\pm}1.69\;years$ F $9.30{\pm}1.16\;years$ 2nd Molar M $14.38{\pm}1.73\;years$ F $13.96{\pm}1.63\;years$ 2. Sexual differences in same age group at given calcification stage were not significant statistically. 3. The developmental order in mandibular permanent teeth was as follows; a) central incisor, b) lateral incisor, c) 1st molar, d) canine and 1st premolar, e) 2nd premolar, f) 2nd molar.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.533-540
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• 2000

Gonadal development, gametogenesis, reproductive cycle, gonad index, flesh weight rate, and first sexual maturity of the turban shell, Lunella coronata coreensis were investigated by histological observation. The materials used were collected monthly from the rocky intertidal zone of Daehang-ri, Buan-gun, Jeollabuk-do, on the west coast of Korea, from July 1998 to June 1999. Sex of L coronata coreensis was separate. The gonad was widely located in the spirals of the visceral mass buried in the digestive gland. The ovary and testis were composed of a number of oogenic follicles and speymatogenic follicles, respectively. Monthly variations in the gonad index increased from March ($23.86{\pm}3.73$) when the water temperature increased and reached the maximun in July ($49.76{\pm}6.47$). And then, the gonad index sharply decreased in September ($15.58{\pm}2.33$). The flesh weight rate ranged from $25.2{\%}$ to $32.3{\%}$, and its variation showed a similar pattern to the gonad index. Individuals $<5.9 mm$ in shell height could not take part in reproduction in both sexes. Percentages of first sexual maturity of female and male specimens ranging from $7.0{\~}7.9 mm$ in shell heights were $84.6{\%}\;and\;91.7{\%}$, respectively, and $100{\%}$ in those over 8.0 mm in shell height in both sexes took part in reproduction. By studying the monthly changes of the morphological features and sizes of germ cells during gametogenesis in the gonad, the reproductive cycle of this species could be devided into five successive stages: early active (December to April), late active (January to July), ripe (May to August), spawning (July to September), and recovery (September to March). The spawning period of this species was once a year between July and September, and the main spawning occurred in July when the seawater temperature reached above $24.8^{\circ}C$. The fully ripe eggs were $150{\~}160\;{\mu}m$ in diameter.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.3
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• pp.312-319
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• 2020

Precocious puberty (PP) is defined as the early development of secondary sexual characteristics (before the ages of 8 years in girls and 9 years in boys). The aim of this study is to identify characteristics of the dental maturity in girls with PP that discriminate them from normal healthy girls. This study included 99 girls aged 6 - 8 years with PP and 99 girls without past medical history of same chronological age (control group). The study was performed on 198 panoramic radiographs (99 PP girls, 99 control group girls). Demirjian method was used to evaluate the panoramic radiographs and determine dental maturity. Difference in dental maturity score and tooth formation stages between the two groups were analyzed. The PP group showed significant higher maturity score than control group. Among mandibular teeth, mandibular 2nd premolar and 2nd molar were significantly more mature in the PP group than control group. Logistic regression analysis showed that mandibular 2nd molar was only significant predictor for PP girls.

• Mycobiology
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• v.28 no.4
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• pp.197-201
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• 2000

The distribution and occurrence of aquatic zoosporic and terrestrial fungi were investigated in 21 well waters in Assiut governorate, Egypt. Using a zoospore capture technique, 923 colonies of aquatic freshwater fungi were recovered from well waters, out of which 811 colonies reached sexual maturity. These colonies were assigned to 23 species which belong to 11 genera. The most common genera were Achlya, Saprolegnia and Dictyuchus. Using two types of media, 35 species in addition to 2 varieties of terrestrial fungi which belong to 18 genera were also recovered. The most frequent glucophilic genera (recovered on glucose-Czapek's agar at $28^{\circ}C$) were Aspergillus, Penicillium and Fusarium. The results obtained on cellulose-Czapek's agar at $2^{\circ}C$ were basically similar to those on glucose agar and the most frequent genera were Aspergillus, Penicillium and Fusarium followed by Chaetomium and Cephalosporium.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.16-16
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• 2002

The egg productivity of the chick is represented by the number of egg produced, egg weight, and sexual maturity, which are regulated by various endocrine factors. Although there were some reports that insulin-like growth factor-I (IGF-Ⅰ) affected egg production, studies on any correlation between IGFs and egg productivity were not reported in poultry. The objectives of the present study were to examine the IGFs profile and egg productivity in both KNOC and laying hen (Saver) and to investigate the relationship of IGFs with egg productivity. Whole blood was collected every 10 wk until 60 wks. (omitted)

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.4
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• pp.375-378
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• 1995

Three month old 600 ducklings of Khaki Campbell/KC Desi and KC X Desi were reared for a period of 13 months in the villages surrounding Bangladesh Agricultural University in order to study the economic traits of duck with and without extra feed to scavenging system of rearing. KC attained earlier sexual maturity followed by KC X Desi and Desi ducks and crossbred showed closeness to sire breed for this trait, KC X Desi found heavier and produce more eggs than their parental breeds. KC showed higher hatchability followed by KC X Desi and Desi ducks were more resistant followed by KC X Desi and KC to diseases. Extra feeding were found more beneficial to ducks irrespective of breed and types.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.3
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• pp.200-207
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• 2013

This paper presents the mesh selectivity of a net pot for common octopus Octopus minor for the sustainable resources management of common octopus. The filed experiments were carried out the total 10 times in the southern part of coastal sea in Korea from March to May in 2010 using net pots of five different mesh sizes (16, 18, 20, 22 and 26mm). The test of size selectivity, indicated a 50% selection value on the logistic master curve of 3.195, whereby 50% of individuals with a mantle size of approximately 70.3mm selected a mesh size of 22mm. Considering that 50% of common octopus entering sexual maturity have a mantle size of 70.6mm, the optimum mesh size should be equal to, or larger than 22mm.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.4
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• pp.361-368
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• 1991

In two experiments 640 starcross replacement pullets between 25 and 154 days of age were fed ad libitum on either of 16 diets formed by the combination of $4CP{\times}4ME$ levels to study the interaction of CP and ME on growth performances. In both experiments, feed intake decreased, but protein intake, energy intake, live weight gain and feed conversion efficiency increased and sexual maturity hastened with the increase of dietary protein and/or energy level. The protein conversion efficiency decreased with the increase of dietary protein level. The energy conversion efficiency, however, did not show any relationship with dietary energy level. There was a greater improvement of growth performance due to simultaneous increase of dietary protein and energy level than that of increasing protein or energy alone.